| /**************************************************************************** |
| * |
| * freetype.h |
| * |
| * FreeType high-level API and common types (specification only). |
| * |
| * Copyright (C) 1996-2023 by |
| * David Turner, Robert Wilhelm, and Werner Lemberg. |
| * |
| * This file is part of the FreeType project, and may only be used, |
| * modified, and distributed under the terms of the FreeType project |
| * license, LICENSE.TXT. By continuing to use, modify, or distribute |
| * this file you indicate that you have read the license and |
| * understand and accept it fully. |
| * |
| */ |
| |
| |
| #ifndef FREETYPE_H_ |
| #define FREETYPE_H_ |
| |
| |
| #include <ft2build.h> |
| #include FT_CONFIG_CONFIG_H |
| #include <freetype/fttypes.h> |
| #include <freetype/fterrors.h> |
| |
| |
| FT_BEGIN_HEADER |
| |
| |
| |
| /************************************************************************** |
| * |
| * @section: |
| * preamble |
| * |
| * @title: |
| * Preamble |
| * |
| * @abstract: |
| * What FreeType is and isn't |
| * |
| * @description: |
| * FreeType is a library that provides access to glyphs in font files. It |
| * scales the glyph images and their metrics to a requested size, and it |
| * rasterizes the glyph images to produce pixel or subpixel alpha coverage |
| * bitmaps. |
| * |
| * Note that FreeType is _not_ a text layout engine. You have to use |
| * higher-level libraries like HarfBuzz, Pango, or ICU for that. |
| * |
| * Note also that FreeType does _not_ perform alpha blending or |
| * compositing the resulting bitmaps or pixmaps by itself. Use your |
| * favourite graphics library (for example, Cairo or Skia) to further |
| * process FreeType's output. |
| * |
| */ |
| |
| |
| /************************************************************************** |
| * |
| * @section: |
| * header_inclusion |
| * |
| * @title: |
| * FreeType's header inclusion scheme |
| * |
| * @abstract: |
| * How client applications should include FreeType header files. |
| * |
| * @description: |
| * To be as flexible as possible (and for historical reasons), you must |
| * load file `ft2build.h` first before other header files, for example |
| * |
| * ``` |
| * #include <ft2build.h> |
| * |
| * #include <freetype/freetype.h> |
| * #include <freetype/ftoutln.h> |
| * ``` |
| */ |
| |
| |
| /************************************************************************** |
| * |
| * @section: |
| * user_allocation |
| * |
| * @title: |
| * User allocation |
| * |
| * @abstract: |
| * How client applications should allocate FreeType data structures. |
| * |
| * @description: |
| * FreeType assumes that structures allocated by the user and passed as |
| * arguments are zeroed out except for the actual data. In other words, |
| * it is recommended to use `calloc` (or variants of it) instead of |
| * `malloc` for allocation. |
| * |
| */ |
| |
| |
| |
| /*************************************************************************/ |
| /*************************************************************************/ |
| /* */ |
| /* B A S I C T Y P E S */ |
| /* */ |
| /*************************************************************************/ |
| /*************************************************************************/ |
| |
| |
| /************************************************************************** |
| * |
| * @section: |
| * base_interface |
| * |
| * @title: |
| * Base Interface |
| * |
| * @abstract: |
| * The FreeType~2 base font interface. |
| * |
| * @description: |
| * This section describes the most important public high-level API |
| * functions of FreeType~2. |
| * |
| * @order: |
| * FT_Library |
| * FT_Face |
| * FT_Size |
| * FT_GlyphSlot |
| * FT_CharMap |
| * FT_Encoding |
| * FT_ENC_TAG |
| * |
| * FT_FaceRec |
| * |
| * FT_FACE_FLAG_SCALABLE |
| * FT_FACE_FLAG_FIXED_SIZES |
| * FT_FACE_FLAG_FIXED_WIDTH |
| * FT_FACE_FLAG_HORIZONTAL |
| * FT_FACE_FLAG_VERTICAL |
| * FT_FACE_FLAG_COLOR |
| * FT_FACE_FLAG_SFNT |
| * FT_FACE_FLAG_CID_KEYED |
| * FT_FACE_FLAG_TRICKY |
| * FT_FACE_FLAG_KERNING |
| * FT_FACE_FLAG_MULTIPLE_MASTERS |
| * FT_FACE_FLAG_VARIATION |
| * FT_FACE_FLAG_GLYPH_NAMES |
| * FT_FACE_FLAG_EXTERNAL_STREAM |
| * FT_FACE_FLAG_HINTER |
| * FT_FACE_FLAG_SVG |
| * FT_FACE_FLAG_SBIX |
| * FT_FACE_FLAG_SBIX_OVERLAY |
| * |
| * FT_HAS_HORIZONTAL |
| * FT_HAS_VERTICAL |
| * FT_HAS_KERNING |
| * FT_HAS_FIXED_SIZES |
| * FT_HAS_GLYPH_NAMES |
| * FT_HAS_COLOR |
| * FT_HAS_MULTIPLE_MASTERS |
| * FT_HAS_SVG |
| * FT_HAS_SBIX |
| * FT_HAS_SBIX_OVERLAY |
| * |
| * FT_IS_SFNT |
| * FT_IS_SCALABLE |
| * FT_IS_FIXED_WIDTH |
| * FT_IS_CID_KEYED |
| * FT_IS_TRICKY |
| * FT_IS_NAMED_INSTANCE |
| * FT_IS_VARIATION |
| * |
| * FT_STYLE_FLAG_BOLD |
| * FT_STYLE_FLAG_ITALIC |
| * |
| * FT_SizeRec |
| * FT_Size_Metrics |
| * |
| * FT_GlyphSlotRec |
| * FT_Glyph_Metrics |
| * FT_SubGlyph |
| * |
| * FT_Bitmap_Size |
| * |
| * FT_Init_FreeType |
| * FT_Done_FreeType |
| * |
| * FT_New_Face |
| * FT_Done_Face |
| * FT_Reference_Face |
| * FT_New_Memory_Face |
| * FT_Face_Properties |
| * FT_Open_Face |
| * FT_Open_Args |
| * FT_Parameter |
| * FT_Attach_File |
| * FT_Attach_Stream |
| * |
| * FT_Set_Char_Size |
| * FT_Set_Pixel_Sizes |
| * FT_Request_Size |
| * FT_Select_Size |
| * FT_Size_Request_Type |
| * FT_Size_RequestRec |
| * FT_Size_Request |
| * FT_Set_Transform |
| * FT_Get_Transform |
| * FT_Load_Glyph |
| * FT_Get_Char_Index |
| * FT_Get_First_Char |
| * FT_Get_Next_Char |
| * FT_Load_Char |
| * |
| * FT_OPEN_MEMORY |
| * FT_OPEN_STREAM |
| * FT_OPEN_PATHNAME |
| * FT_OPEN_DRIVER |
| * FT_OPEN_PARAMS |
| * |
| * FT_LOAD_DEFAULT |
| * FT_LOAD_RENDER |
| * FT_LOAD_MONOCHROME |
| * FT_LOAD_LINEAR_DESIGN |
| * FT_LOAD_NO_SCALE |
| * FT_LOAD_NO_HINTING |
| * FT_LOAD_NO_BITMAP |
| * FT_LOAD_SBITS_ONLY |
| * FT_LOAD_NO_AUTOHINT |
| * FT_LOAD_COLOR |
| * |
| * FT_LOAD_VERTICAL_LAYOUT |
| * FT_LOAD_IGNORE_TRANSFORM |
| * FT_LOAD_FORCE_AUTOHINT |
| * FT_LOAD_NO_RECURSE |
| * FT_LOAD_PEDANTIC |
| * |
| * FT_LOAD_TARGET_NORMAL |
| * FT_LOAD_TARGET_LIGHT |
| * FT_LOAD_TARGET_MONO |
| * FT_LOAD_TARGET_LCD |
| * FT_LOAD_TARGET_LCD_V |
| * |
| * FT_LOAD_TARGET_MODE |
| * |
| * FT_Render_Glyph |
| * FT_Render_Mode |
| * FT_Get_Kerning |
| * FT_Kerning_Mode |
| * FT_Get_Track_Kerning |
| * |
| * FT_CharMapRec |
| * FT_Select_Charmap |
| * FT_Set_Charmap |
| * FT_Get_Charmap_Index |
| * |
| * FT_Get_Name_Index |
| * FT_Get_Glyph_Name |
| * FT_Get_Postscript_Name |
| * FT_Get_FSType_Flags |
| * FT_Get_SubGlyph_Info |
| * |
| * FT_Face_Internal |
| * FT_Size_Internal |
| * FT_Slot_Internal |
| * |
| * FT_FACE_FLAG_XXX |
| * FT_STYLE_FLAG_XXX |
| * FT_OPEN_XXX |
| * FT_LOAD_XXX |
| * FT_LOAD_TARGET_XXX |
| * FT_SUBGLYPH_FLAG_XXX |
| * FT_FSTYPE_XXX |
| * |
| * FT_HAS_FAST_GLYPHS |
| * |
| */ |
| |
| |
| /************************************************************************** |
| * |
| * @struct: |
| * FT_Glyph_Metrics |
| * |
| * @description: |
| * A structure to model the metrics of a single glyph. The values are |
| * expressed in 26.6 fractional pixel format; if the flag |
| * @FT_LOAD_NO_SCALE has been used while loading the glyph, values are |
| * expressed in font units instead. |
| * |
| * @fields: |
| * width :: |
| * The glyph's width. |
| * |
| * height :: |
| * The glyph's height. |
| * |
| * horiBearingX :: |
| * Left side bearing for horizontal layout. |
| * |
| * horiBearingY :: |
| * Top side bearing for horizontal layout. |
| * |
| * horiAdvance :: |
| * Advance width for horizontal layout. |
| * |
| * vertBearingX :: |
| * Left side bearing for vertical layout. |
| * |
| * vertBearingY :: |
| * Top side bearing for vertical layout. Larger positive values mean |
| * further below the vertical glyph origin. |
| * |
| * vertAdvance :: |
| * Advance height for vertical layout. Positive values mean the glyph |
| * has a positive advance downward. |
| * |
| * @note: |
| * If not disabled with @FT_LOAD_NO_HINTING, the values represent |
| * dimensions of the hinted glyph (in case hinting is applicable). |
| * |
| * Stroking a glyph with an outside border does not increase |
| * `horiAdvance` or `vertAdvance`; you have to manually adjust these |
| * values to account for the added width and height. |
| * |
| * FreeType doesn't use the 'VORG' table data for CFF fonts because it |
| * doesn't have an interface to quickly retrieve the glyph height. The |
| * y~coordinate of the vertical origin can be simply computed as |
| * `vertBearingY + height` after loading a glyph. |
| */ |
| typedef struct FT_Glyph_Metrics_ |
| { |
| FT_Pos width; |
| FT_Pos height; |
| |
| FT_Pos horiBearingX; |
| FT_Pos horiBearingY; |
| FT_Pos horiAdvance; |
| |
| FT_Pos vertBearingX; |
| FT_Pos vertBearingY; |
| FT_Pos vertAdvance; |
| |
| } FT_Glyph_Metrics; |
| |
| |
| /************************************************************************** |
| * |
| * @struct: |
| * FT_Bitmap_Size |
| * |
| * @description: |
| * This structure models the metrics of a bitmap strike (i.e., a set of |
| * glyphs for a given point size and resolution) in a bitmap font. It is |
| * used for the `available_sizes` field of @FT_Face. |
| * |
| * @fields: |
| * height :: |
| * The vertical distance, in pixels, between two consecutive baselines. |
| * It is always positive. |
| * |
| * width :: |
| * The average width, in pixels, of all glyphs in the strike. |
| * |
| * size :: |
| * The nominal size of the strike in 26.6 fractional points. This |
| * field is not very useful. |
| * |
| * x_ppem :: |
| * The horizontal ppem (nominal width) in 26.6 fractional pixels. |
| * |
| * y_ppem :: |
| * The vertical ppem (nominal height) in 26.6 fractional pixels. |
| * |
| * @note: |
| * Windows FNT: |
| * The nominal size given in a FNT font is not reliable. If the driver |
| * finds it incorrect, it sets `size` to some calculated values, and |
| * `x_ppem` and `y_ppem` to the pixel width and height given in the |
| * font, respectively. |
| * |
| * TrueType embedded bitmaps: |
| * `size`, `width`, and `height` values are not contained in the bitmap |
| * strike itself. They are computed from the global font parameters. |
| */ |
| typedef struct FT_Bitmap_Size_ |
| { |
| FT_Short height; |
| FT_Short width; |
| |
| FT_Pos size; |
| |
| FT_Pos x_ppem; |
| FT_Pos y_ppem; |
| |
| } FT_Bitmap_Size; |
| |
| |
| /*************************************************************************/ |
| /*************************************************************************/ |
| /* */ |
| /* O B J E C T C L A S S E S */ |
| /* */ |
| /*************************************************************************/ |
| /*************************************************************************/ |
| |
| /************************************************************************** |
| * |
| * @type: |
| * FT_Library |
| * |
| * @description: |
| * A handle to a FreeType library instance. Each 'library' is completely |
| * independent from the others; it is the 'root' of a set of objects like |
| * fonts, faces, sizes, etc. |
| * |
| * It also embeds a memory manager (see @FT_Memory), as well as a |
| * scan-line converter object (see @FT_Raster). |
| * |
| * [Since 2.5.6] In multi-threaded applications it is easiest to use one |
| * `FT_Library` object per thread. In case this is too cumbersome, a |
| * single `FT_Library` object across threads is possible also, as long as |
| * a mutex lock is used around @FT_New_Face and @FT_Done_Face. |
| * |
| * @note: |
| * Library objects are normally created by @FT_Init_FreeType, and |
| * destroyed with @FT_Done_FreeType. If you need reference-counting |
| * (cf. @FT_Reference_Library), use @FT_New_Library and @FT_Done_Library. |
| */ |
| typedef struct FT_LibraryRec_ *FT_Library; |
| |
| |
| /************************************************************************** |
| * |
| * @section: |
| * module_management |
| * |
| */ |
| |
| /************************************************************************** |
| * |
| * @type: |
| * FT_Module |
| * |
| * @description: |
| * A handle to a given FreeType module object. A module can be a font |
| * driver, a renderer, or anything else that provides services to the |
| * former. |
| */ |
| typedef struct FT_ModuleRec_* FT_Module; |
| |
| |
| /************************************************************************** |
| * |
| * @type: |
| * FT_Driver |
| * |
| * @description: |
| * A handle to a given FreeType font driver object. A font driver is a |
| * module capable of creating faces from font files. |
| */ |
| typedef struct FT_DriverRec_* FT_Driver; |
| |
| |
| /************************************************************************** |
| * |
| * @type: |
| * FT_Renderer |
| * |
| * @description: |
| * A handle to a given FreeType renderer. A renderer is a module in |
| * charge of converting a glyph's outline image to a bitmap. It supports |
| * a single glyph image format, and one or more target surface depths. |
| */ |
| typedef struct FT_RendererRec_* FT_Renderer; |
| |
| |
| /************************************************************************** |
| * |
| * @section: |
| * base_interface |
| * |
| */ |
| |
| /************************************************************************** |
| * |
| * @type: |
| * FT_Face |
| * |
| * @description: |
| * A handle to a typographic face object. A face object models a given |
| * typeface, in a given style. |
| * |
| * @note: |
| * A face object also owns a single @FT_GlyphSlot object, as well as one |
| * or more @FT_Size objects. |
| * |
| * Use @FT_New_Face or @FT_Open_Face to create a new face object from a |
| * given filepath or a custom input stream. |
| * |
| * Use @FT_Done_Face to destroy it (along with its slot and sizes). |
| * |
| * An `FT_Face` object can only be safely used from one thread at a time. |
| * Similarly, creation and destruction of `FT_Face` with the same |
| * @FT_Library object can only be done from one thread at a time. On the |
| * other hand, functions like @FT_Load_Glyph and its siblings are |
| * thread-safe and do not need the lock to be held as long as the same |
| * `FT_Face` object is not used from multiple threads at the same time. |
| * |
| * @also: |
| * See @FT_FaceRec for the publicly accessible fields of a given face |
| * object. |
| */ |
| typedef struct FT_FaceRec_* FT_Face; |
| |
| |
| /************************************************************************** |
| * |
| * @type: |
| * FT_Size |
| * |
| * @description: |
| * A handle to an object that models a face scaled to a given character |
| * size. |
| * |
| * @note: |
| * An @FT_Face has one _active_ `FT_Size` object that is used by |
| * functions like @FT_Load_Glyph to determine the scaling transformation |
| * that in turn is used to load and hint glyphs and metrics. |
| * |
| * A newly created `FT_Size` object contains only meaningless zero values. |
| * You must use @FT_Set_Char_Size, @FT_Set_Pixel_Sizes, @FT_Request_Size |
| * or even @FT_Select_Size to change the content (i.e., the scaling |
| * values) of the active `FT_Size`. Otherwise, the scaling and hinting |
| * will not be performed. |
| * |
| * You can use @FT_New_Size to create additional size objects for a given |
| * @FT_Face, but they won't be used by other functions until you activate |
| * it through @FT_Activate_Size. Only one size can be activated at any |
| * given time per face. |
| * |
| * @also: |
| * See @FT_SizeRec for the publicly accessible fields of a given size |
| * object. |
| */ |
| typedef struct FT_SizeRec_* FT_Size; |
| |
| |
| /************************************************************************** |
| * |
| * @type: |
| * FT_GlyphSlot |
| * |
| * @description: |
| * A handle to a given 'glyph slot'. A slot is a container that can hold |
| * any of the glyphs contained in its parent face. |
| * |
| * In other words, each time you call @FT_Load_Glyph or @FT_Load_Char, |
| * the slot's content is erased by the new glyph data, i.e., the glyph's |
| * metrics, its image (bitmap or outline), and other control information. |
| * |
| * @also: |
| * See @FT_GlyphSlotRec for the publicly accessible glyph fields. |
| */ |
| typedef struct FT_GlyphSlotRec_* FT_GlyphSlot; |
| |
| |
| /************************************************************************** |
| * |
| * @type: |
| * FT_CharMap |
| * |
| * @description: |
| * A handle to a character map (usually abbreviated to 'charmap'). A |
| * charmap is used to translate character codes in a given encoding into |
| * glyph indexes for its parent's face. Some font formats may provide |
| * several charmaps per font. |
| * |
| * Each face object owns zero or more charmaps, but only one of them can |
| * be 'active', providing the data used by @FT_Get_Char_Index or |
| * @FT_Load_Char. |
| * |
| * The list of available charmaps in a face is available through the |
| * `face->num_charmaps` and `face->charmaps` fields of @FT_FaceRec. |
| * |
| * The currently active charmap is available as `face->charmap`. You |
| * should call @FT_Set_Charmap to change it. |
| * |
| * @note: |
| * When a new face is created (either through @FT_New_Face or |
| * @FT_Open_Face), the library looks for a Unicode charmap within the |
| * list and automatically activates it. If there is no Unicode charmap, |
| * FreeType doesn't set an 'active' charmap. |
| * |
| * @also: |
| * See @FT_CharMapRec for the publicly accessible fields of a given |
| * character map. |
| */ |
| typedef struct FT_CharMapRec_* FT_CharMap; |
| |
| |
| /************************************************************************** |
| * |
| * @macro: |
| * FT_ENC_TAG |
| * |
| * @description: |
| * This macro converts four-letter tags into an unsigned long. It is |
| * used to define 'encoding' identifiers (see @FT_Encoding). |
| * |
| * @note: |
| * Since many 16-bit compilers don't like 32-bit enumerations, you should |
| * redefine this macro in case of problems to something like this: |
| * |
| * ``` |
| * #define FT_ENC_TAG( value, a, b, c, d ) value |
| * ``` |
| * |
| * to get a simple enumeration without assigning special numbers. |
| */ |
| |
| #ifndef FT_ENC_TAG |
| |
| #define FT_ENC_TAG( value, a, b, c, d ) \ |
| value = ( ( FT_STATIC_BYTE_CAST( FT_UInt32, a ) << 24 ) | \ |
| ( FT_STATIC_BYTE_CAST( FT_UInt32, b ) << 16 ) | \ |
| ( FT_STATIC_BYTE_CAST( FT_UInt32, c ) << 8 ) | \ |
| FT_STATIC_BYTE_CAST( FT_UInt32, d ) ) |
| |
| #endif /* FT_ENC_TAG */ |
| |
| |
| /************************************************************************** |
| * |
| * @enum: |
| * FT_Encoding |
| * |
| * @description: |
| * An enumeration to specify character sets supported by charmaps. Used |
| * in the @FT_Select_Charmap API function. |
| * |
| * @note: |
| * Despite the name, this enumeration lists specific character |
| * repertoires (i.e., charsets), and not text encoding methods (e.g., |
| * UTF-8, UTF-16, etc.). |
| * |
| * Other encodings might be defined in the future. |
| * |
| * @values: |
| * FT_ENCODING_NONE :: |
| * The encoding value~0 is reserved for all formats except BDF, PCF, |
| * and Windows FNT; see below for more information. |
| * |
| * FT_ENCODING_UNICODE :: |
| * The Unicode character set. This value covers all versions of the |
| * Unicode repertoire, including ASCII and Latin-1. Most fonts include |
| * a Unicode charmap, but not all of them. |
| * |
| * For example, if you want to access Unicode value U+1F028 (and the |
| * font contains it), use value 0x1F028 as the input value for |
| * @FT_Get_Char_Index. |
| * |
| * FT_ENCODING_MS_SYMBOL :: |
| * Microsoft Symbol encoding, used to encode mathematical symbols and |
| * wingdings. For more information, see |
| * 'https://www.microsoft.com/typography/otspec/recom.htm#non-standard-symbol-fonts', |
| * 'http://www.kostis.net/charsets/symbol.htm', and |
| * 'http://www.kostis.net/charsets/wingding.htm'. |
| * |
| * This encoding uses character codes from the PUA (Private Unicode |
| * Area) in the range U+F020-U+F0FF. |
| * |
| * FT_ENCODING_SJIS :: |
| * Shift JIS encoding for Japanese. More info at |
| * 'https://en.wikipedia.org/wiki/Shift_JIS'. See note on multi-byte |
| * encodings below. |
| * |
| * FT_ENCODING_PRC :: |
| * Corresponds to encoding systems mainly for Simplified Chinese as |
| * used in People's Republic of China (PRC). The encoding layout is |
| * based on GB~2312 and its supersets GBK and GB~18030. |
| * |
| * FT_ENCODING_BIG5 :: |
| * Corresponds to an encoding system for Traditional Chinese as used in |
| * Taiwan and Hong Kong. |
| * |
| * FT_ENCODING_WANSUNG :: |
| * Corresponds to the Korean encoding system known as Extended Wansung |
| * (MS Windows code page 949). For more information see |
| * 'https://www.unicode.org/Public/MAPPINGS/VENDORS/MICSFT/WindowsBestFit/bestfit949.txt'. |
| * |
| * FT_ENCODING_JOHAB :: |
| * The Korean standard character set (KS~C 5601-1992), which |
| * corresponds to MS Windows code page 1361. This character set |
| * includes all possible Hangul character combinations. |
| * |
| * FT_ENCODING_ADOBE_LATIN_1 :: |
| * Corresponds to a Latin-1 encoding as defined in a Type~1 PostScript |
| * font. It is limited to 256 character codes. |
| * |
| * FT_ENCODING_ADOBE_STANDARD :: |
| * Adobe Standard encoding, as found in Type~1, CFF, and OpenType/CFF |
| * fonts. It is limited to 256 character codes. |
| * |
| * FT_ENCODING_ADOBE_EXPERT :: |
| * Adobe Expert encoding, as found in Type~1, CFF, and OpenType/CFF |
| * fonts. It is limited to 256 character codes. |
| * |
| * FT_ENCODING_ADOBE_CUSTOM :: |
| * Corresponds to a custom encoding, as found in Type~1, CFF, and |
| * OpenType/CFF fonts. It is limited to 256 character codes. |
| * |
| * FT_ENCODING_APPLE_ROMAN :: |
| * Apple roman encoding. Many TrueType and OpenType fonts contain a |
| * charmap for this 8-bit encoding, since older versions of Mac OS are |
| * able to use it. |
| * |
| * FT_ENCODING_OLD_LATIN_2 :: |
| * This value is deprecated and was neither used nor reported by |
| * FreeType. Don't use or test for it. |
| * |
| * FT_ENCODING_MS_SJIS :: |
| * Same as FT_ENCODING_SJIS. Deprecated. |
| * |
| * FT_ENCODING_MS_GB2312 :: |
| * Same as FT_ENCODING_PRC. Deprecated. |
| * |
| * FT_ENCODING_MS_BIG5 :: |
| * Same as FT_ENCODING_BIG5. Deprecated. |
| * |
| * FT_ENCODING_MS_WANSUNG :: |
| * Same as FT_ENCODING_WANSUNG. Deprecated. |
| * |
| * FT_ENCODING_MS_JOHAB :: |
| * Same as FT_ENCODING_JOHAB. Deprecated. |
| * |
| * @note: |
| * When loading a font, FreeType makes a Unicode charmap active if |
| * possible (either if the font provides such a charmap, or if FreeType |
| * can synthesize one from PostScript glyph name dictionaries; in either |
| * case, the charmap is tagged with `FT_ENCODING_UNICODE`). If such a |
| * charmap is synthesized, it is placed at the first position of the |
| * charmap array. |
| * |
| * All other encodings are considered legacy and tagged only if |
| * explicitly defined in the font file. Otherwise, `FT_ENCODING_NONE` is |
| * used. |
| * |
| * `FT_ENCODING_NONE` is set by the BDF and PCF drivers if the charmap is |
| * neither Unicode nor ISO-8859-1 (otherwise it is set to |
| * `FT_ENCODING_UNICODE`). Use @FT_Get_BDF_Charset_ID to find out which |
| * encoding is really present. If, for example, the `cs_registry` field |
| * is 'KOI8' and the `cs_encoding` field is 'R', the font is encoded in |
| * KOI8-R. |
| * |
| * `FT_ENCODING_NONE` is always set (with a single exception) by the |
| * winfonts driver. Use @FT_Get_WinFNT_Header and examine the `charset` |
| * field of the @FT_WinFNT_HeaderRec structure to find out which encoding |
| * is really present. For example, @FT_WinFNT_ID_CP1251 (204) means |
| * Windows code page 1251 (for Russian). |
| * |
| * `FT_ENCODING_NONE` is set if `platform_id` is @TT_PLATFORM_MACINTOSH |
| * and `encoding_id` is not `TT_MAC_ID_ROMAN` (otherwise it is set to |
| * `FT_ENCODING_APPLE_ROMAN`). |
| * |
| * If `platform_id` is @TT_PLATFORM_MACINTOSH, use the function |
| * @FT_Get_CMap_Language_ID to query the Mac language ID that may be |
| * needed to be able to distinguish Apple encoding variants. See |
| * |
| * https://www.unicode.org/Public/MAPPINGS/VENDORS/APPLE/Readme.txt |
| * |
| * to get an idea how to do that. Basically, if the language ID is~0, |
| * don't use it, otherwise subtract 1 from the language ID. Then examine |
| * `encoding_id`. If, for example, `encoding_id` is `TT_MAC_ID_ROMAN` |
| * and the language ID (minus~1) is `TT_MAC_LANGID_GREEK`, it is the |
| * Greek encoding, not Roman. `TT_MAC_ID_ARABIC` with |
| * `TT_MAC_LANGID_FARSI` means the Farsi variant of the Arabic encoding. |
| */ |
| typedef enum FT_Encoding_ |
| { |
| FT_ENC_TAG( FT_ENCODING_NONE, 0, 0, 0, 0 ), |
| |
| FT_ENC_TAG( FT_ENCODING_MS_SYMBOL, 's', 'y', 'm', 'b' ), |
| FT_ENC_TAG( FT_ENCODING_UNICODE, 'u', 'n', 'i', 'c' ), |
| |
| FT_ENC_TAG( FT_ENCODING_SJIS, 's', 'j', 'i', 's' ), |
| FT_ENC_TAG( FT_ENCODING_PRC, 'g', 'b', ' ', ' ' ), |
| FT_ENC_TAG( FT_ENCODING_BIG5, 'b', 'i', 'g', '5' ), |
| FT_ENC_TAG( FT_ENCODING_WANSUNG, 'w', 'a', 'n', 's' ), |
| FT_ENC_TAG( FT_ENCODING_JOHAB, 'j', 'o', 'h', 'a' ), |
| |
| /* for backward compatibility */ |
| FT_ENCODING_GB2312 = FT_ENCODING_PRC, |
| FT_ENCODING_MS_SJIS = FT_ENCODING_SJIS, |
| FT_ENCODING_MS_GB2312 = FT_ENCODING_PRC, |
| FT_ENCODING_MS_BIG5 = FT_ENCODING_BIG5, |
| FT_ENCODING_MS_WANSUNG = FT_ENCODING_WANSUNG, |
| FT_ENCODING_MS_JOHAB = FT_ENCODING_JOHAB, |
| |
| FT_ENC_TAG( FT_ENCODING_ADOBE_STANDARD, 'A', 'D', 'O', 'B' ), |
| FT_ENC_TAG( FT_ENCODING_ADOBE_EXPERT, 'A', 'D', 'B', 'E' ), |
| FT_ENC_TAG( FT_ENCODING_ADOBE_CUSTOM, 'A', 'D', 'B', 'C' ), |
| FT_ENC_TAG( FT_ENCODING_ADOBE_LATIN_1, 'l', 'a', 't', '1' ), |
| |
| FT_ENC_TAG( FT_ENCODING_OLD_LATIN_2, 'l', 'a', 't', '2' ), |
| |
| FT_ENC_TAG( FT_ENCODING_APPLE_ROMAN, 'a', 'r', 'm', 'n' ) |
| |
| } FT_Encoding; |
| |
| |
| /* these constants are deprecated; use the corresponding `FT_Encoding` */ |
| /* values instead */ |
| #define ft_encoding_none FT_ENCODING_NONE |
| #define ft_encoding_unicode FT_ENCODING_UNICODE |
| #define ft_encoding_symbol FT_ENCODING_MS_SYMBOL |
| #define ft_encoding_latin_1 FT_ENCODING_ADOBE_LATIN_1 |
| #define ft_encoding_latin_2 FT_ENCODING_OLD_LATIN_2 |
| #define ft_encoding_sjis FT_ENCODING_SJIS |
| #define ft_encoding_gb2312 FT_ENCODING_PRC |
| #define ft_encoding_big5 FT_ENCODING_BIG5 |
| #define ft_encoding_wansung FT_ENCODING_WANSUNG |
| #define ft_encoding_johab FT_ENCODING_JOHAB |
| |
| #define ft_encoding_adobe_standard FT_ENCODING_ADOBE_STANDARD |
| #define ft_encoding_adobe_expert FT_ENCODING_ADOBE_EXPERT |
| #define ft_encoding_adobe_custom FT_ENCODING_ADOBE_CUSTOM |
| #define ft_encoding_apple_roman FT_ENCODING_APPLE_ROMAN |
| |
| |
| /************************************************************************** |
| * |
| * @struct: |
| * FT_CharMapRec |
| * |
| * @description: |
| * The base charmap structure. |
| * |
| * @fields: |
| * face :: |
| * A handle to the parent face object. |
| * |
| * encoding :: |
| * An @FT_Encoding tag identifying the charmap. Use this with |
| * @FT_Select_Charmap. |
| * |
| * platform_id :: |
| * An ID number describing the platform for the following encoding ID. |
| * This comes directly from the TrueType specification and gets |
| * emulated for other formats. |
| * |
| * encoding_id :: |
| * A platform-specific encoding number. This also comes from the |
| * TrueType specification and gets emulated similarly. |
| */ |
| typedef struct FT_CharMapRec_ |
| { |
| FT_Face face; |
| FT_Encoding encoding; |
| FT_UShort platform_id; |
| FT_UShort encoding_id; |
| |
| } FT_CharMapRec; |
| |
| |
| /*************************************************************************/ |
| /*************************************************************************/ |
| /* */ |
| /* B A S E O B J E C T C L A S S E S */ |
| /* */ |
| /*************************************************************************/ |
| /*************************************************************************/ |
| |
| |
| /************************************************************************** |
| * |
| * @type: |
| * FT_Face_Internal |
| * |
| * @description: |
| * An opaque handle to an `FT_Face_InternalRec` structure that models the |
| * private data of a given @FT_Face object. |
| * |
| * This structure might change between releases of FreeType~2 and is not |
| * generally available to client applications. |
| */ |
| typedef struct FT_Face_InternalRec_* FT_Face_Internal; |
| |
| |
| /************************************************************************** |
| * |
| * @struct: |
| * FT_FaceRec |
| * |
| * @description: |
| * FreeType root face class structure. A face object models a typeface |
| * in a font file. |
| * |
| * @fields: |
| * num_faces :: |
| * The number of faces in the font file. Some font formats can have |
| * multiple faces in a single font file. |
| * |
| * face_index :: |
| * This field holds two different values. Bits 0-15 are the index of |
| * the face in the font file (starting with value~0). They are set |
| * to~0 if there is only one face in the font file. |
| * |
| * [Since 2.6.1] Bits 16-30 are relevant to GX and OpenType variation |
| * fonts only, holding the named instance index for the current face |
| * index (starting with value~1; value~0 indicates font access without |
| * a named instance). For non-variation fonts, bits 16-30 are ignored. |
| * If we have the third named instance of face~4, say, `face_index` is |
| * set to 0x00030004. |
| * |
| * Bit 31 is always zero (this is, `face_index` is always a positive |
| * value). |
| * |
| * [Since 2.9] Changing the design coordinates with |
| * @FT_Set_Var_Design_Coordinates or @FT_Set_Var_Blend_Coordinates does |
| * not influence the named instance index value (only |
| * @FT_Set_Named_Instance does that). |
| * |
| * face_flags :: |
| * A set of bit flags that give important information about the face; |
| * see @FT_FACE_FLAG_XXX for the details. |
| * |
| * style_flags :: |
| * The lower 16~bits contain a set of bit flags indicating the style of |
| * the face; see @FT_STYLE_FLAG_XXX for the details. |
| * |
| * [Since 2.6.1] Bits 16-30 hold the number of named instances |
| * available for the current face if we have a GX or OpenType variation |
| * (sub)font. Bit 31 is always zero (this is, `style_flags` is always |
| * a positive value). Note that a variation font has always at least |
| * one named instance, namely the default instance. |
| * |
| * num_glyphs :: |
| * The number of glyphs in the face. If the face is scalable and has |
| * sbits (see `num_fixed_sizes`), it is set to the number of outline |
| * glyphs. |
| * |
| * For CID-keyed fonts (not in an SFNT wrapper) this value gives the |
| * highest CID used in the font. |
| * |
| * family_name :: |
| * The face's family name. This is an ASCII string, usually in |
| * English, that describes the typeface's family (like 'Times New |
| * Roman', 'Bodoni', 'Garamond', etc). This is a least common |
| * denominator used to list fonts. Some formats (TrueType & OpenType) |
| * provide localized and Unicode versions of this string. Applications |
| * should use the format-specific interface to access them. Can be |
| * `NULL` (e.g., in fonts embedded in a PDF file). |
| * |
| * In case the font doesn't provide a specific family name entry, |
| * FreeType tries to synthesize one, deriving it from other name |
| * entries. |
| * |
| * style_name :: |
| * The face's style name. This is an ASCII string, usually in English, |
| * that describes the typeface's style (like 'Italic', 'Bold', |
| * 'Condensed', etc). Not all font formats provide a style name, so |
| * this field is optional, and can be set to `NULL`. As for |
| * `family_name`, some formats provide localized and Unicode versions |
| * of this string. Applications should use the format-specific |
| * interface to access them. |
| * |
| * num_fixed_sizes :: |
| * The number of bitmap strikes in the face. Even if the face is |
| * scalable, there might still be bitmap strikes, which are called |
| * 'sbits' in that case. |
| * |
| * available_sizes :: |
| * An array of @FT_Bitmap_Size for all bitmap strikes in the face. It |
| * is set to `NULL` if there is no bitmap strike. |
| * |
| * Note that FreeType tries to sanitize the strike data since they are |
| * sometimes sloppy or incorrect, but this can easily fail. |
| * |
| * num_charmaps :: |
| * The number of charmaps in the face. |
| * |
| * charmaps :: |
| * An array of the charmaps of the face. |
| * |
| * generic :: |
| * A field reserved for client uses. See the @FT_Generic type |
| * description. |
| * |
| * bbox :: |
| * The font bounding box. Coordinates are expressed in font units (see |
| * `units_per_EM`). The box is large enough to contain any glyph from |
| * the font. Thus, `bbox.yMax` can be seen as the 'maximum ascender', |
| * and `bbox.yMin` as the 'minimum descender'. Only relevant for |
| * scalable formats. |
| * |
| * Note that the bounding box might be off by (at least) one pixel for |
| * hinted fonts. See @FT_Size_Metrics for further discussion. |
| * |
| * Note that the bounding box does not vary in OpenType variable fonts |
| * and should only be used in relation to the default instance. |
| * |
| * units_per_EM :: |
| * The number of font units per EM square for this face. This is |
| * typically 2048 for TrueType fonts, and 1000 for Type~1 fonts. Only |
| * relevant for scalable formats. |
| * |
| * ascender :: |
| * The typographic ascender of the face, expressed in font units. For |
| * font formats not having this information, it is set to `bbox.yMax`. |
| * Only relevant for scalable formats. |
| * |
| * descender :: |
| * The typographic descender of the face, expressed in font units. For |
| * font formats not having this information, it is set to `bbox.yMin`. |
| * Note that this field is negative for values below the baseline. |
| * Only relevant for scalable formats. |
| * |
| * height :: |
| * This value is the vertical distance between two consecutive |
| * baselines, expressed in font units. It is always positive. Only |
| * relevant for scalable formats. |
| * |
| * If you want the global glyph height, use `ascender - descender`. |
| * |
| * max_advance_width :: |
| * The maximum advance width, in font units, for all glyphs in this |
| * face. This can be used to make word wrapping computations faster. |
| * Only relevant for scalable formats. |
| * |
| * max_advance_height :: |
| * The maximum advance height, in font units, for all glyphs in this |
| * face. This is only relevant for vertical layouts, and is set to |
| * `height` for fonts that do not provide vertical metrics. Only |
| * relevant for scalable formats. |
| * |
| * underline_position :: |
| * The position, in font units, of the underline line for this face. |
| * It is the center of the underlining stem. Only relevant for |
| * scalable formats. |
| * |
| * underline_thickness :: |
| * The thickness, in font units, of the underline for this face. Only |
| * relevant for scalable formats. |
| * |
| * glyph :: |
| * The face's associated glyph slot(s). |
| * |
| * size :: |
| * The current active size for this face. |
| * |
| * charmap :: |
| * The current active charmap for this face. |
| * |
| * @note: |
| * Fields may be changed after a call to @FT_Attach_File or |
| * @FT_Attach_Stream. |
| * |
| * For an OpenType variation font, the values of the following fields can |
| * change after a call to @FT_Set_Var_Design_Coordinates (and friends) if |
| * the font contains an 'MVAR' table: `ascender`, `descender`, `height`, |
| * `underline_position`, and `underline_thickness`. |
| * |
| * Especially for TrueType fonts see also the documentation for |
| * @FT_Size_Metrics. |
| */ |
| typedef struct FT_FaceRec_ |
| { |
| FT_Long num_faces; |
| FT_Long face_index; |
| |
| FT_Long face_flags; |
| FT_Long style_flags; |
| |
| FT_Long num_glyphs; |
| |
| FT_String* family_name; |
| FT_String* style_name; |
| |
| FT_Int num_fixed_sizes; |
| FT_Bitmap_Size* available_sizes; |
| |
| FT_Int num_charmaps; |
| FT_CharMap* charmaps; |
| |
| FT_Generic generic; |
| |
| /*# The following member variables (down to `underline_thickness`) */ |
| /*# are only relevant to scalable outlines; cf. @FT_Bitmap_Size */ |
| /*# for bitmap fonts. */ |
| FT_BBox bbox; |
| |
| FT_UShort units_per_EM; |
| FT_Short ascender; |
| FT_Short descender; |
| FT_Short height; |
| |
| FT_Short max_advance_width; |
| FT_Short max_advance_height; |
| |
| FT_Short underline_position; |
| FT_Short underline_thickness; |
| |
| FT_GlyphSlot glyph; |
| FT_Size size; |
| FT_CharMap charmap; |
| |
| /*@private begin */ |
| |
| FT_Driver driver; |
| FT_Memory memory; |
| FT_Stream stream; |
| |
| FT_ListRec sizes_list; |
| |
| FT_Generic autohint; /* face-specific auto-hinter data */ |
| void* extensions; /* unused */ |
| |
| FT_Face_Internal internal; |
| |
| /*@private end */ |
| |
| } FT_FaceRec; |
| |
| |
| /************************************************************************** |
| * |
| * @enum: |
| * FT_FACE_FLAG_XXX |
| * |
| * @description: |
| * A list of bit flags used in the `face_flags` field of the @FT_FaceRec |
| * structure. They inform client applications of properties of the |
| * corresponding face. |
| * |
| * @values: |
| * FT_FACE_FLAG_SCALABLE :: |
| * The face contains outline glyphs. Note that a face can contain |
| * bitmap strikes also, i.e., a face can have both this flag and |
| * @FT_FACE_FLAG_FIXED_SIZES set. |
| * |
| * FT_FACE_FLAG_FIXED_SIZES :: |
| * The face contains bitmap strikes. See also the `num_fixed_sizes` |
| * and `available_sizes` fields of @FT_FaceRec. |
| * |
| * FT_FACE_FLAG_FIXED_WIDTH :: |
| * The face contains fixed-width characters (like Courier, Lucida, |
| * MonoType, etc.). |
| * |
| * FT_FACE_FLAG_SFNT :: |
| * The face uses the SFNT storage scheme. For now, this means TrueType |
| * and OpenType. |
| * |
| * FT_FACE_FLAG_HORIZONTAL :: |
| * The face contains horizontal glyph metrics. This should be set for |
| * all common formats. |
| * |
| * FT_FACE_FLAG_VERTICAL :: |
| * The face contains vertical glyph metrics. This is only available in |
| * some formats, not all of them. |
| * |
| * FT_FACE_FLAG_KERNING :: |
| * The face contains kerning information. If set, the kerning distance |
| * can be retrieved using the function @FT_Get_Kerning. Otherwise the |
| * function always returns the vector (0,0). Note that FreeType |
| * doesn't handle kerning data from the SFNT 'GPOS' table (as present |
| * in many OpenType fonts). |
| * |
| * FT_FACE_FLAG_FAST_GLYPHS :: |
| * THIS FLAG IS DEPRECATED. DO NOT USE OR TEST IT. |
| * |
| * FT_FACE_FLAG_MULTIPLE_MASTERS :: |
| * The face contains multiple masters and is capable of interpolating |
| * between them. Supported formats are Adobe MM, TrueType GX, and |
| * OpenType variation fonts. |
| * |
| * See section @multiple_masters for API details. |
| * |
| * FT_FACE_FLAG_GLYPH_NAMES :: |
| * The face contains glyph names, which can be retrieved using |
| * @FT_Get_Glyph_Name. Note that some TrueType fonts contain broken |
| * glyph name tables. Use the function @FT_Has_PS_Glyph_Names when |
| * needed. |
| * |
| * FT_FACE_FLAG_EXTERNAL_STREAM :: |
| * Used internally by FreeType to indicate that a face's stream was |
| * provided by the client application and should not be destroyed when |
| * @FT_Done_Face is called. Don't read or test this flag. |
| * |
| * FT_FACE_FLAG_HINTER :: |
| * The font driver has a hinting machine of its own. For example, with |
| * TrueType fonts, it makes sense to use data from the SFNT 'gasp' |
| * table only if the native TrueType hinting engine (with the bytecode |
| * interpreter) is available and active. |
| * |
| * FT_FACE_FLAG_CID_KEYED :: |
| * The face is CID-keyed. In that case, the face is not accessed by |
| * glyph indices but by CID values. For subsetted CID-keyed fonts this |
| * has the consequence that not all index values are a valid argument |
| * to @FT_Load_Glyph. Only the CID values for which corresponding |
| * glyphs in the subsetted font exist make `FT_Load_Glyph` return |
| * successfully; in all other cases you get an |
| * `FT_Err_Invalid_Argument` error. |
| * |
| * Note that CID-keyed fonts that are in an SFNT wrapper (this is, all |
| * OpenType/CFF fonts) don't have this flag set since the glyphs are |
| * accessed in the normal way (using contiguous indices); the |
| * 'CID-ness' isn't visible to the application. |
| * |
| * FT_FACE_FLAG_TRICKY :: |
| * The face is 'tricky', this is, it always needs the font format's |
| * native hinting engine to get a reasonable result. A typical example |
| * is the old Chinese font `mingli.ttf` (but not `mingliu.ttc`) that |
| * uses TrueType bytecode instructions to move and scale all of its |
| * subglyphs. |
| * |
| * It is not possible to auto-hint such fonts using |
| * @FT_LOAD_FORCE_AUTOHINT; it will also ignore @FT_LOAD_NO_HINTING. |
| * You have to set both @FT_LOAD_NO_HINTING and @FT_LOAD_NO_AUTOHINT to |
| * really disable hinting; however, you probably never want this except |
| * for demonstration purposes. |
| * |
| * Currently, there are about a dozen TrueType fonts in the list of |
| * tricky fonts; they are hard-coded in file `ttobjs.c`. |
| * |
| * FT_FACE_FLAG_COLOR :: |
| * [Since 2.5.1] The face has color glyph tables. See @FT_LOAD_COLOR |
| * for more information. |
| * |
| * FT_FACE_FLAG_VARIATION :: |
| * [Since 2.9] Set if the current face (or named instance) has been |
| * altered with @FT_Set_MM_Design_Coordinates, |
| * @FT_Set_Var_Design_Coordinates, or @FT_Set_Var_Blend_Coordinates. |
| * This flag is unset by a call to @FT_Set_Named_Instance. |
| * |
| * FT_FACE_FLAG_SVG :: |
| * [Since 2.12] The face has an 'SVG~' OpenType table. |
| * |
| * FT_FACE_FLAG_SBIX :: |
| * [Since 2.12] The face has an 'sbix' OpenType table *and* outlines. |
| * For such fonts, @FT_FACE_FLAG_SCALABLE is not set by default to |
| * retain backward compatibility. |
| * |
| * FT_FACE_FLAG_SBIX_OVERLAY :: |
| * [Since 2.12] The face has an 'sbix' OpenType table where outlines |
| * should be drawn on top of bitmap strikes. |
| * |
| */ |
| #define FT_FACE_FLAG_SCALABLE ( 1L << 0 ) |
| #define FT_FACE_FLAG_FIXED_SIZES ( 1L << 1 ) |
| #define FT_FACE_FLAG_FIXED_WIDTH ( 1L << 2 ) |
| #define FT_FACE_FLAG_SFNT ( 1L << 3 ) |
| #define FT_FACE_FLAG_HORIZONTAL ( 1L << 4 ) |
| #define FT_FACE_FLAG_VERTICAL ( 1L << 5 ) |
| #define FT_FACE_FLAG_KERNING ( 1L << 6 ) |
| #define FT_FACE_FLAG_FAST_GLYPHS ( 1L << 7 ) |
| #define FT_FACE_FLAG_MULTIPLE_MASTERS ( 1L << 8 ) |
| #define FT_FACE_FLAG_GLYPH_NAMES ( 1L << 9 ) |
| #define FT_FACE_FLAG_EXTERNAL_STREAM ( 1L << 10 ) |
| #define FT_FACE_FLAG_HINTER ( 1L << 11 ) |
| #define FT_FACE_FLAG_CID_KEYED ( 1L << 12 ) |
| #define FT_FACE_FLAG_TRICKY ( 1L << 13 ) |
| #define FT_FACE_FLAG_COLOR ( 1L << 14 ) |
| #define FT_FACE_FLAG_VARIATION ( 1L << 15 ) |
| #define FT_FACE_FLAG_SVG ( 1L << 16 ) |
| #define FT_FACE_FLAG_SBIX ( 1L << 17 ) |
| #define FT_FACE_FLAG_SBIX_OVERLAY ( 1L << 18 ) |
| |
| |
| /************************************************************************** |
| * |
| * @macro: |
| * FT_HAS_HORIZONTAL |
| * |
| * @description: |
| * A macro that returns true whenever a face object contains horizontal |
| * metrics (this is true for all font formats though). |
| * |
| * @also: |
| * @FT_HAS_VERTICAL can be used to check for vertical metrics. |
| * |
| */ |
| #define FT_HAS_HORIZONTAL( face ) \ |
| ( !!( (face)->face_flags & FT_FACE_FLAG_HORIZONTAL ) ) |
| |
| |
| /************************************************************************** |
| * |
| * @macro: |
| * FT_HAS_VERTICAL |
| * |
| * @description: |
| * A macro that returns true whenever a face object contains real |
| * vertical metrics (and not only synthesized ones). |
| * |
| */ |
| #define FT_HAS_VERTICAL( face ) \ |
| ( !!( (face)->face_flags & FT_FACE_FLAG_VERTICAL ) ) |
| |
| |
| /************************************************************************** |
| * |
| * @macro: |
| * FT_HAS_KERNING |
| * |
| * @description: |
| * A macro that returns true whenever a face object contains kerning data |
| * that can be accessed with @FT_Get_Kerning. |
| * |
| */ |
| #define FT_HAS_KERNING( face ) \ |
| ( !!( (face)->face_flags & FT_FACE_FLAG_KERNING ) ) |
| |
| |
| /************************************************************************** |
| * |
| * @macro: |
| * FT_IS_SCALABLE |
| * |
| * @description: |
| * A macro that returns true whenever a face object contains a scalable |
| * font face (true for TrueType, Type~1, Type~42, CID, OpenType/CFF, and |
| * PFR font formats). |
| * |
| */ |
| #define FT_IS_SCALABLE( face ) \ |
| ( !!( (face)->face_flags & FT_FACE_FLAG_SCALABLE ) ) |
| |
| |
| /************************************************************************** |
| * |
| * @macro: |
| * FT_IS_SFNT |
| * |
| * @description: |
| * A macro that returns true whenever a face object contains a font whose |
| * format is based on the SFNT storage scheme. This usually means: |
| * TrueType fonts, OpenType fonts, as well as SFNT-based embedded bitmap |
| * fonts. |
| * |
| * If this macro is true, all functions defined in @FT_SFNT_NAMES_H and |
| * @FT_TRUETYPE_TABLES_H are available. |
| * |
| */ |
| #define FT_IS_SFNT( face ) \ |
| ( !!( (face)->face_flags & FT_FACE_FLAG_SFNT ) ) |
| |
| |
| /************************************************************************** |
| * |
| * @macro: |
| * FT_IS_FIXED_WIDTH |
| * |
| * @description: |
| * A macro that returns true whenever a face object contains a font face |
| * that contains fixed-width (or 'monospace', 'fixed-pitch', etc.) |
| * glyphs. |
| * |
| */ |
| #define FT_IS_FIXED_WIDTH( face ) \ |
| ( !!( (face)->face_flags & FT_FACE_FLAG_FIXED_WIDTH ) ) |
| |
| |
| /************************************************************************** |
| * |
| * @macro: |
| * FT_HAS_FIXED_SIZES |
| * |
| * @description: |
| * A macro that returns true whenever a face object contains some |
| * embedded bitmaps. See the `available_sizes` field of the @FT_FaceRec |
| * structure. |
| * |
| */ |
| #define FT_HAS_FIXED_SIZES( face ) \ |
| ( !!( (face)->face_flags & FT_FACE_FLAG_FIXED_SIZES ) ) |
| |
| |
| /************************************************************************** |
| * |
| * @macro: |
| * FT_HAS_FAST_GLYPHS |
| * |
| * @description: |
| * Deprecated. |
| * |
| */ |
| #define FT_HAS_FAST_GLYPHS( face ) 0 |
| |
| |
| /************************************************************************** |
| * |
| * @macro: |
| * FT_HAS_GLYPH_NAMES |
| * |
| * @description: |
| * A macro that returns true whenever a face object contains some glyph |
| * names that can be accessed through @FT_Get_Glyph_Name. |
| * |
| */ |
| #define FT_HAS_GLYPH_NAMES( face ) \ |
| ( !!( (face)->face_flags & FT_FACE_FLAG_GLYPH_NAMES ) ) |
| |
| |
| /************************************************************************** |
| * |
| * @macro: |
| * FT_HAS_MULTIPLE_MASTERS |
| * |
| * @description: |
| * A macro that returns true whenever a face object contains some |
| * multiple masters. The functions provided by @FT_MULTIPLE_MASTERS_H |
| * are then available to choose the exact design you want. |
| * |
| */ |
| #define FT_HAS_MULTIPLE_MASTERS( face ) \ |
| ( !!( (face)->face_flags & FT_FACE_FLAG_MULTIPLE_MASTERS ) ) |
| |
| |
| /************************************************************************** |
| * |
| * @macro: |
| * FT_IS_NAMED_INSTANCE |
| * |
| * @description: |
| * A macro that returns true whenever a face object is a named instance |
| * of a GX or OpenType variation font. |
| * |
| * [Since 2.9] Changing the design coordinates with |
| * @FT_Set_Var_Design_Coordinates or @FT_Set_Var_Blend_Coordinates does |
| * not influence the return value of this macro (only |
| * @FT_Set_Named_Instance does that). |
| * |
| * @since: |
| * 2.7 |
| * |
| */ |
| #define FT_IS_NAMED_INSTANCE( face ) \ |
| ( !!( (face)->face_index & 0x7FFF0000L ) ) |
| |
| |
| /************************************************************************** |
| * |
| * @macro: |
| * FT_IS_VARIATION |
| * |
| * @description: |
| * A macro that returns true whenever a face object has been altered by |
| * @FT_Set_MM_Design_Coordinates, @FT_Set_Var_Design_Coordinates, or |
| * @FT_Set_Var_Blend_Coordinates. |
| * |
| * @since: |
| * 2.9 |
| * |
| */ |
| #define FT_IS_VARIATION( face ) \ |
| ( !!( (face)->face_flags & FT_FACE_FLAG_VARIATION ) ) |
| |
| |
| /************************************************************************** |
| * |
| * @macro: |
| * FT_IS_CID_KEYED |
| * |
| * @description: |
| * A macro that returns true whenever a face object contains a CID-keyed |
| * font. See the discussion of @FT_FACE_FLAG_CID_KEYED for more details. |
| * |
| * If this macro is true, all functions defined in @FT_CID_H are |
| * available. |
| * |
| */ |
| #define FT_IS_CID_KEYED( face ) \ |
| ( !!( (face)->face_flags & FT_FACE_FLAG_CID_KEYED ) ) |
| |
| |
| /************************************************************************** |
| * |
| * @macro: |
| * FT_IS_TRICKY |
| * |
| * @description: |
| * A macro that returns true whenever a face represents a 'tricky' font. |
| * See the discussion of @FT_FACE_FLAG_TRICKY for more details. |
| * |
| */ |
| #define FT_IS_TRICKY( face ) \ |
| ( !!( (face)->face_flags & FT_FACE_FLAG_TRICKY ) ) |
| |
| |
| /************************************************************************** |
| * |
| * @macro: |
| * FT_HAS_COLOR |
| * |
| * @description: |
| * A macro that returns true whenever a face object contains tables for |
| * color glyphs. |
| * |
| * @since: |
| * 2.5.1 |
| * |
| */ |
| #define FT_HAS_COLOR( face ) \ |
| ( !!( (face)->face_flags & FT_FACE_FLAG_COLOR ) ) |
| |
| |
| /************************************************************************** |
| * |
| * @macro: |
| * FT_HAS_SVG |
| * |
| * @description: |
| * A macro that returns true whenever a face object contains an 'SVG~' |
| * OpenType table. |
| * |
| * @since: |
| * 2.12 |
| */ |
| #define FT_HAS_SVG( face ) \ |
| ( !!( (face)->face_flags & FT_FACE_FLAG_SVG ) ) |
| |
| |
| /************************************************************************** |
| * |
| * @macro: |
| * FT_HAS_SBIX |
| * |
| * @description: |
| * A macro that returns true whenever a face object contains an 'sbix' |
| * OpenType table *and* outline glyphs. |
| * |
| * Currently, FreeType only supports bitmap glyphs in PNG format for this |
| * table (i.e., JPEG and TIFF formats are unsupported, as are |
| * Apple-specific formats not part of the OpenType specification). |
| * |
| * @note: |
| * For backward compatibility, a font with an 'sbix' table is treated as |
| * a bitmap-only face. Using @FT_Open_Face with |
| * @FT_PARAM_TAG_IGNORE_SBIX, an application can switch off 'sbix' |
| * handling so that the face is treated as an ordinary outline font with |
| * scalable outlines. |
| * |
| * Here is some pseudo code that roughly illustrates how to implement |
| * 'sbix' handling according to the OpenType specification. |
| * |
| * ``` |
| * if ( FT_HAS_SBIX( face ) ) |
| * { |
| * // open font as a scalable one without sbix handling |
| * FT_Face face2; |
| * FT_Parameter param = { FT_PARAM_TAG_IGNORE_SBIX, NULL }; |
| * FT_Open_Args args = { FT_OPEN_PARAMS | ..., |
| * ..., |
| * 1, ¶m }; |
| * |
| * |
| * FT_Open_Face( library, &args, 0, &face2 ); |
| * |
| * <sort `face->available_size` as necessary into |
| * `preferred_sizes`[*]> |
| * |
| * for ( i = 0; i < face->num_fixed_sizes; i++ ) |
| * { |
| * size = preferred_sizes[i].size; |
| * |
| * error = FT_Set_Pixel_Sizes( face, size, size ); |
| * <error handling omitted> |
| * |
| * // check whether we have a glyph in a bitmap strike |
| * error = FT_Load_Glyph( face, |
| * glyph_index, |
| * FT_LOAD_SBITS_ONLY | |
| * FT_LOAD_BITMAP_METRICS_ONLY ); |
| * if ( error == FT_Err_Invalid_Argument ) |
| * continue; |
| * else if ( error ) |
| * <other error handling omitted> |
| * else |
| * break; |
| * } |
| * |
| * if ( i != face->num_fixed_sizes ) |
| * <load embedded bitmap with `FT_Load_Glyph`, |
| * scale it, display it, etc.> |
| * |
| * if ( i == face->num_fixed_sizes || |
| * FT_HAS_SBIX_OVERLAY( face ) ) |
| * <use `face2` to load outline glyph with `FT_Load_Glyph`, |
| * scale it, display it on top of the bitmap, etc.> |
| * } |
| * ``` |
| * |
| * [*] Assuming a target value of 400dpi and available strike sizes 100, |
| * 200, 300, and 400dpi, a possible order might be [400, 200, 300, 100]: |
| * scaling 200dpi to 400dpi usually gives better results than scaling |
| * 300dpi to 400dpi; it is also much faster. However, scaling 100dpi to |
| * 400dpi can yield a too pixelated result, thus the preference might be |
| * 300dpi over 100dpi. |
| * |
| * @since: |
| * 2.12 |
| */ |
| #define FT_HAS_SBIX( face ) \ |
| ( !!( (face)->face_flags & FT_FACE_FLAG_SBIX ) ) |
| |
| |
| /************************************************************************** |
| * |
| * @macro: |
| * FT_HAS_SBIX_OVERLAY |
| * |
| * @description: |
| * A macro that returns true whenever a face object contains an 'sbix' |
| * OpenType table with bit~1 in its `flags` field set, instructing the |
| * application to overlay the bitmap strike with the corresponding |
| * outline glyph. See @FT_HAS_SBIX for pseudo code how to use it. |
| * |
| * @since: |
| * 2.12 |
| */ |
| #define FT_HAS_SBIX_OVERLAY( face ) \ |
| ( !!( (face)->face_flags & FT_FACE_FLAG_SBIX_OVERLAY ) ) |
| |
| |
| /************************************************************************** |
| * |
| * @enum: |
| * FT_STYLE_FLAG_XXX |
| * |
| * @description: |
| * A list of bit flags to indicate the style of a given face. These are |
| * used in the `style_flags` field of @FT_FaceRec. |
| * |
| * @values: |
| * FT_STYLE_FLAG_ITALIC :: |
| * The face style is italic or oblique. |
| * |
| * FT_STYLE_FLAG_BOLD :: |
| * The face is bold. |
| * |
| * @note: |
| * The style information as provided by FreeType is very basic. More |
| * details are beyond the scope and should be done on a higher level (for |
| * example, by analyzing various fields of the 'OS/2' table in SFNT based |
| * fonts). |
| */ |
| #define FT_STYLE_FLAG_ITALIC ( 1 << 0 ) |
| #define FT_STYLE_FLAG_BOLD ( 1 << 1 ) |
| |
| |
| /************************************************************************** |
| * |
| * @type: |
| * FT_Size_Internal |
| * |
| * @description: |
| * An opaque handle to an `FT_Size_InternalRec` structure, used to model |
| * private data of a given @FT_Size object. |
| */ |
| typedef struct FT_Size_InternalRec_* FT_Size_Internal; |
| |
| |
| /************************************************************************** |
| * |
| * @struct: |
| * FT_Size_Metrics |
| * |
| * @description: |
| * The size metrics structure gives the metrics of a size object. |
| * |
| * @fields: |
| * x_ppem :: |
| * The width of the scaled EM square in pixels, hence the term 'ppem' |
| * (pixels per EM). It is also referred to as 'nominal width'. |
| * |
| * y_ppem :: |
| * The height of the scaled EM square in pixels, hence the term 'ppem' |
| * (pixels per EM). It is also referred to as 'nominal height'. |
| * |
| * x_scale :: |
| * A 16.16 fractional scaling value to convert horizontal metrics from |
| * font units to 26.6 fractional pixels. Only relevant for scalable |
| * font formats. |
| * |
| * y_scale :: |
| * A 16.16 fractional scaling value to convert vertical metrics from |
| * font units to 26.6 fractional pixels. Only relevant for scalable |
| * font formats. |
| * |
| * ascender :: |
| * The ascender in 26.6 fractional pixels, rounded up to an integer |
| * value. See @FT_FaceRec for the details. |
| * |
| * descender :: |
| * The descender in 26.6 fractional pixels, rounded down to an integer |
| * value. See @FT_FaceRec for the details. |
| * |
| * height :: |
| * The height in 26.6 fractional pixels, rounded to an integer value. |
| * See @FT_FaceRec for the details. |
| * |
| * max_advance :: |
| * The maximum advance width in 26.6 fractional pixels, rounded to an |
| * integer value. See @FT_FaceRec for the details. |
| * |
| * @note: |
| * The scaling values, if relevant, are determined first during a size |
| * changing operation. The remaining fields are then set by the driver. |
| * For scalable formats, they are usually set to scaled values of the |
| * corresponding fields in @FT_FaceRec. Some values like ascender or |
| * descender are rounded for historical reasons; more precise values (for |
| * outline fonts) can be derived by scaling the corresponding @FT_FaceRec |
| * values manually, with code similar to the following. |
| * |
| * ``` |
| * scaled_ascender = FT_MulFix( face->ascender, |
| * size_metrics->y_scale ); |
| * ``` |
| * |
| * Note that due to glyph hinting and the selected rendering mode these |
| * values are usually not exact; consequently, they must be treated as |
| * unreliable with an error margin of at least one pixel! |
| * |
| * Indeed, the only way to get the exact metrics is to render _all_ |
| * glyphs. As this would be a definite performance hit, it is up to |
| * client applications to perform such computations. |
| * |
| * The `FT_Size_Metrics` structure is valid for bitmap fonts also. |
| * |
| * |
| * **TrueType fonts with native bytecode hinting** |
| * |
| * All applications that handle TrueType fonts with native hinting must |
| * be aware that TTFs expect different rounding of vertical font |
| * dimensions. The application has to cater for this, especially if it |
| * wants to rely on a TTF's vertical data (for example, to properly align |
| * box characters vertically). |
| * |
| * Only the application knows _in advance_ that it is going to use native |
| * hinting for TTFs! FreeType, on the other hand, selects the hinting |
| * mode not at the time of creating an @FT_Size object but much later, |
| * namely while calling @FT_Load_Glyph. |
| * |
| * Here is some pseudo code that illustrates a possible solution. |
| * |
| * ``` |
| * font_format = FT_Get_Font_Format( face ); |
| * |
| * if ( !strcmp( font_format, "TrueType" ) && |
| * do_native_bytecode_hinting ) |
| * { |
| * ascender = ROUND( FT_MulFix( face->ascender, |
| * size_metrics->y_scale ) ); |
| * descender = ROUND( FT_MulFix( face->descender, |
| * size_metrics->y_scale ) ); |
| * } |
| * else |
| * { |
| * ascender = size_metrics->ascender; |
| * descender = size_metrics->descender; |
| * } |
| * |
| * height = size_metrics->height; |
| * max_advance = size_metrics->max_advance; |
| * ``` |
| */ |
| typedef struct FT_Size_Metrics_ |
| { |
| FT_UShort x_ppem; /* horizontal pixels per EM */ |
| FT_UShort y_ppem; /* vertical pixels per EM */ |
| |
| FT_Fixed x_scale; /* scaling values used to convert font */ |
| FT_Fixed y_scale; /* units to 26.6 fractional pixels */ |
| |
| FT_Pos ascender; /* ascender in 26.6 frac. pixels */ |
| FT_Pos descender; /* descender in 26.6 frac. pixels */ |
| FT_Pos height; /* text height in 26.6 frac. pixels */ |
| FT_Pos max_advance; /* max horizontal advance, in 26.6 pixels */ |
| |
| } FT_Size_Metrics; |
| |
| |
| /************************************************************************** |
| * |
| * @struct: |
| * FT_SizeRec |
| * |
| * @description: |
| * FreeType root size class structure. A size object models a face |
| * object at a given size. |
| * |
| * @fields: |
| * face :: |
| * Handle to the parent face object. |
| * |
| * generic :: |
| * A typeless pointer, unused by the FreeType library or any of its |
| * drivers. It can be used by client applications to link their own |
| * data to each size object. |
| * |
| * metrics :: |
| * Metrics for this size object. This field is read-only. |
| */ |
| typedef struct FT_SizeRec_ |
| { |
| FT_Face face; /* parent face object */ |
| FT_Generic generic; /* generic pointer for client uses */ |
| FT_Size_Metrics metrics; /* size metrics */ |
| FT_Size_Internal internal; |
| |
| } FT_SizeRec; |
| |
| |
| /************************************************************************** |
| * |
| * @struct: |
| * FT_SubGlyph |
| * |
| * @description: |
| * The subglyph structure is an internal object used to describe |
| * subglyphs (for example, in the case of composites). |
| * |
| * @note: |
| * The subglyph implementation is not part of the high-level API, hence |
| * the forward structure declaration. |
| * |
| * You can however retrieve subglyph information with |
| * @FT_Get_SubGlyph_Info. |
| */ |
| typedef struct FT_SubGlyphRec_* FT_SubGlyph; |
| |
| |
| /************************************************************************** |
| * |
| * @type: |
| * FT_Slot_Internal |
| * |
| * @description: |
| * An opaque handle to an `FT_Slot_InternalRec` structure, used to model |
| * private data of a given @FT_GlyphSlot object. |
| */ |
| typedef struct FT_Slot_InternalRec_* FT_Slot_Internal; |
| |
| |
| /************************************************************************** |
| * |
| * @struct: |
| * FT_GlyphSlotRec |
| * |
| * @description: |
| * FreeType root glyph slot class structure. A glyph slot is a container |
| * where individual glyphs can be loaded, be they in outline or bitmap |
| * format. |
| * |
| * @fields: |
| * library :: |
| * A handle to the FreeType library instance this slot belongs to. |
| * |
| * face :: |
| * A handle to the parent face object. |
| * |
| * next :: |
| * In some cases (like some font tools), several glyph slots per face |
| * object can be a good thing. As this is rare, the glyph slots are |
| * listed through a direct, single-linked list using its `next` field. |
| * |
| * glyph_index :: |
| * [Since 2.10] The glyph index passed as an argument to @FT_Load_Glyph |
| * while initializing the glyph slot. |
| * |
| * generic :: |
| * A typeless pointer unused by the FreeType library or any of its |
| * drivers. It can be used by client applications to link their own |
| * data to each glyph slot object. |
| * |
| * metrics :: |
| * The metrics of the last loaded glyph in the slot. The returned |
| * values depend on the last load flags (see the @FT_Load_Glyph API |
| * function) and can be expressed either in 26.6 fractional pixels or |
| * font units. |
| * |
| * Note that even when the glyph image is transformed, the metrics are |
| * not. |
| * |
| * linearHoriAdvance :: |
| * The advance width of the unhinted glyph. Its value is expressed in |
| * 16.16 fractional pixels, unless @FT_LOAD_LINEAR_DESIGN is set when |
| * loading the glyph. This field can be important to perform correct |
| * WYSIWYG layout. Only relevant for scalable glyphs. |
| * |
| * linearVertAdvance :: |
| * The advance height of the unhinted glyph. Its value is expressed in |
| * 16.16 fractional pixels, unless @FT_LOAD_LINEAR_DESIGN is set when |
| * loading the glyph. This field can be important to perform correct |
| * WYSIWYG layout. Only relevant for scalable glyphs. |
| * |
| * advance :: |
| * This shorthand is, depending on @FT_LOAD_IGNORE_TRANSFORM, the |
| * transformed (hinted) advance width for the glyph, in 26.6 fractional |
| * pixel format. As specified with @FT_LOAD_VERTICAL_LAYOUT, it uses |
| * either the `horiAdvance` or the `vertAdvance` value of `metrics` |
| * field. |
| * |
| * format :: |
| * This field indicates the format of the image contained in the glyph |
| * slot. Typically @FT_GLYPH_FORMAT_BITMAP, @FT_GLYPH_FORMAT_OUTLINE, |
| * or @FT_GLYPH_FORMAT_COMPOSITE, but other values are possible. |
| * |
| * bitmap :: |
| * This field is used as a bitmap descriptor. Note that the address |
| * and content of the bitmap buffer can change between calls of |
| * @FT_Load_Glyph and a few other functions. |
| * |
| * bitmap_left :: |
| * The bitmap's left bearing expressed in integer pixels. |
| * |
| * bitmap_top :: |
| * The bitmap's top bearing expressed in integer pixels. This is the |
| * distance from the baseline to the top-most glyph scanline, upwards |
| * y~coordinates being **positive**. |
| * |
| * outline :: |
| * The outline descriptor for the current glyph image if its format is |
| * @FT_GLYPH_FORMAT_OUTLINE. Once a glyph is loaded, `outline` can be |
| * transformed, distorted, emboldened, etc. However, it must not be |
| * freed. |
| * |
| * [Since 2.10.1] If @FT_LOAD_NO_SCALE is set, outline coordinates of |
| * OpenType variation fonts for a selected instance are internally |
| * handled as 26.6 fractional font units but returned as (rounded) |
| * integers, as expected. To get unrounded font units, don't use |
| * @FT_LOAD_NO_SCALE but load the glyph with @FT_LOAD_NO_HINTING and |
| * scale it, using the font's `units_per_EM` value as the ppem. |
| * |
| * num_subglyphs :: |
| * The number of subglyphs in a composite glyph. This field is only |
| * valid for the composite glyph format that should normally only be |
| * loaded with the @FT_LOAD_NO_RECURSE flag. |
| * |
| * subglyphs :: |
| * An array of subglyph descriptors for composite glyphs. There are |
| * `num_subglyphs` elements in there. Currently internal to FreeType. |
| * |
| * control_data :: |
| * Certain font drivers can also return the control data for a given |
| * glyph image (e.g. TrueType bytecode, Type~1 charstrings, etc.). |
| * This field is a pointer to such data; it is currently internal to |
| * FreeType. |
| * |
| * control_len :: |
| * This is the length in bytes of the control data. Currently internal |
| * to FreeType. |
| * |
| * other :: |
| * Reserved. |
| * |
| * lsb_delta :: |
| * The difference between hinted and unhinted left side bearing while |
| * auto-hinting is active. Zero otherwise. |
| * |
| * rsb_delta :: |
| * The difference between hinted and unhinted right side bearing while |
| * auto-hinting is active. Zero otherwise. |
| * |
| * @note: |
| * If @FT_Load_Glyph is called with default flags (see @FT_LOAD_DEFAULT) |
| * the glyph image is loaded in the glyph slot in its native format |
| * (e.g., an outline glyph for TrueType and Type~1 formats). [Since 2.9] |
| * The prospective bitmap metrics are calculated according to |
| * @FT_LOAD_TARGET_XXX and other flags even for the outline glyph, even |
| * if @FT_LOAD_RENDER is not set. |
| * |
| * This image can later be converted into a bitmap by calling |
| * @FT_Render_Glyph. This function searches the current renderer for the |
| * native image's format, then invokes it. |
| * |
| * The renderer is in charge of transforming the native image through the |
| * slot's face transformation fields, then converting it into a bitmap |
| * that is returned in `slot->bitmap`. |
| * |
| * Note that `slot->bitmap_left` and `slot->bitmap_top` are also used to |
| * specify the position of the bitmap relative to the current pen |
| * position (e.g., coordinates (0,0) on the baseline). Of course, |
| * `slot->format` is also changed to @FT_GLYPH_FORMAT_BITMAP. |
| * |
| * Here is a small pseudo code fragment that shows how to use `lsb_delta` |
| * and `rsb_delta` to do fractional positioning of glyphs: |
| * |
| * ``` |
| * FT_GlyphSlot slot = face->glyph; |
| * FT_Pos origin_x = 0; |
| * |
| * |
| * for all glyphs do |
| * <load glyph with `FT_Load_Glyph'> |
| * |
| * FT_Outline_Translate( slot->outline, origin_x & 63, 0 ); |
| * |
| * <save glyph image, or render glyph, or ...> |
| * |
| * <compute kern between current and next glyph |
| * and add it to `origin_x'> |
| * |
| * origin_x += slot->advance.x; |
| * origin_x += slot->lsb_delta - slot->rsb_delta; |
| * endfor |
| * ``` |
| * |
| * Here is another small pseudo code fragment that shows how to use |
| * `lsb_delta` and `rsb_delta` to improve integer positioning of glyphs: |
| * |
| * ``` |
| * FT_GlyphSlot slot = face->glyph; |
| * FT_Pos origin_x = 0; |
| * FT_Pos prev_rsb_delta = 0; |
| * |
| * |
| * for all glyphs do |
| * <compute kern between current and previous glyph |
| * and add it to `origin_x'> |
| * |
| * <load glyph with `FT_Load_Glyph'> |
| * |
| * if ( prev_rsb_delta - slot->lsb_delta > 32 ) |
| * origin_x -= 64; |
| * else if ( prev_rsb_delta - slot->lsb_delta < -31 ) |
| * origin_x += 64; |
| * |
| * prev_rsb_delta = slot->rsb_delta; |
| * |
| * <save glyph image, or render glyph, or ...> |
| * |
| * origin_x += slot->advance.x; |
| * endfor |
| * ``` |
| * |
| * If you use strong auto-hinting, you **must** apply these delta values! |
| * Otherwise you will experience far too large inter-glyph spacing at |
| * small rendering sizes in most cases. Note that it doesn't harm to use |
| * the above code for other hinting modes also, since the delta values |
| * are zero then. |
| */ |
| typedef struct FT_GlyphSlotRec_ |
| { |
| FT_Library library; |
| FT_Face face; |
| FT_GlyphSlot next; |
| FT_UInt glyph_index; /* new in 2.10; was reserved previously */ |
| FT_Generic generic; |
| |
| FT_Glyph_Metrics metrics; |
| FT_Fixed linearHoriAdvance; |
| FT_Fixed linearVertAdvance; |
| FT_Vector advance; |
| |
| FT_Glyph_Format format; |
| |
| FT_Bitmap bitmap; |
| FT_Int bitmap_left; |
| FT_Int bitmap_top; |
| |
| FT_Outline outline; |
| |
| FT_UInt num_subglyphs; |
| FT_SubGlyph subglyphs; |
| |
| void* control_data; |
| long control_len; |
| |
| FT_Pos lsb_delta; |
| FT_Pos rsb_delta; |
| |
| void* other; |
| |
| FT_Slot_Internal internal; |
| |
| } FT_GlyphSlotRec; |
| |
| |
| /*************************************************************************/ |
| /*************************************************************************/ |
| /* */ |
| /* F U N C T I O N S */ |
| /* */ |
| /*************************************************************************/ |
| /*************************************************************************/ |
| |
| |
| /************************************************************************** |
| * |
| * @function: |
| * FT_Init_FreeType |
| * |
| * @description: |
| * Initialize a new FreeType library object. The set of modules that are |
| * registered by this function is determined at build time. |
| * |
| * @output: |
| * alibrary :: |
| * A handle to a new library object. |
| * |
| * @return: |
| * FreeType error code. 0~means success. |
| * |
| * @note: |
| * In case you want to provide your own memory allocating routines, use |
| * @FT_New_Library instead, followed by a call to @FT_Add_Default_Modules |
| * (or a series of calls to @FT_Add_Module) and |
| * @FT_Set_Default_Properties. |
| * |
| * See the documentation of @FT_Library and @FT_Face for multi-threading |
| * issues. |
| * |
| * If you need reference-counting (cf. @FT_Reference_Library), use |
| * @FT_New_Library and @FT_Done_Library. |
| * |
| * If compilation option `FT_CONFIG_OPTION_ENVIRONMENT_PROPERTIES` is |
| * set, this function reads the `FREETYPE_PROPERTIES` environment |
| * variable to control driver properties. See section @properties for |
| * more. |
| */ |
| FT_EXPORT( FT_Error ) |
| FT_Init_FreeType( FT_Library *alibrary ); |
| |
| |
| /************************************************************************** |
| * |
| * @function: |
| * FT_Done_FreeType |
| * |
| * @description: |
| * Destroy a given FreeType library object and all of its children, |
| * including resources, drivers, faces, sizes, etc. |
| * |
| * @input: |
| * library :: |
| * A handle to the target library object. |
| * |
| * @return: |
| * FreeType error code. 0~means success. |
| */ |
| FT_EXPORT( FT_Error ) |
| FT_Done_FreeType( FT_Library library ); |
| |
| |
| /************************************************************************** |
| * |
| * @enum: |
| * FT_OPEN_XXX |
| * |
| * @description: |
| * A list of bit field constants used within the `flags` field of the |
| * @FT_Open_Args structure. |
| * |
| * @values: |
| * FT_OPEN_MEMORY :: |
| * This is a memory-based stream. |
| * |
| * FT_OPEN_STREAM :: |
| * Copy the stream from the `stream` field. |
| * |
| * FT_OPEN_PATHNAME :: |
| * Create a new input stream from a C~path name. |
| * |
| * FT_OPEN_DRIVER :: |
| * Use the `driver` field. |
| * |
| * FT_OPEN_PARAMS :: |
| * Use the `num_params` and `params` fields. |
| * |
| * @note: |
| * The `FT_OPEN_MEMORY`, `FT_OPEN_STREAM`, and `FT_OPEN_PATHNAME` flags |
| * are mutually exclusive. |
| */ |
| #define FT_OPEN_MEMORY 0x1 |
| #define FT_OPEN_STREAM 0x2 |
| #define FT_OPEN_PATHNAME 0x4 |
| #define FT_OPEN_DRIVER 0x8 |
| #define FT_OPEN_PARAMS 0x10 |
| |
| |
| /* these constants are deprecated; use the corresponding `FT_OPEN_XXX` */ |
| /* values instead */ |
| #define ft_open_memory FT_OPEN_MEMORY |
| #define ft_open_stream FT_OPEN_STREAM |
| #define ft_open_pathname FT_OPEN_PATHNAME |
| #define ft_open_driver FT_OPEN_DRIVER |
| #define ft_open_params FT_OPEN_PARAMS |
| |
| |
| /************************************************************************** |
| * |
| * @struct: |
| * FT_Parameter |
| * |
| * @description: |
| * A simple structure to pass more or less generic parameters to |
| * @FT_Open_Face and @FT_Face_Properties. |
| * |
| * @fields: |
| * tag :: |
| * A four-byte identification tag. |
| * |
| * data :: |
| * A pointer to the parameter data. |
| * |
| * @note: |
| * The ID and function of parameters are driver-specific. See section |
| * @parameter_tags for more information. |
| */ |
| typedef struct FT_Parameter_ |
| { |
| FT_ULong tag; |
| FT_Pointer data; |
| |
| } FT_Parameter; |
| |
| |
| /************************************************************************** |
| * |
| * @struct: |
| * FT_Open_Args |
| * |
| * @description: |
| * A structure to indicate how to open a new font file or stream. A |
| * pointer to such a structure can be used as a parameter for the |
| * functions @FT_Open_Face and @FT_Attach_Stream. |
| * |
| * @fields: |
| * flags :: |
| * A set of bit flags indicating how to use the structure. |
| * |
| * memory_base :: |
| * The first byte of the file in memory. |
| * |
| * memory_size :: |
| * The size in bytes of the file in memory. |
| * |
| * pathname :: |
| * A pointer to an 8-bit file pathname, which must be a C~string (i.e., |
| * no null bytes except at the very end). The pointer is not owned by |
| * FreeType. |
| * |
| * stream :: |
| * A handle to a source stream object. |
| * |
| * driver :: |
| * This field is exclusively used by @FT_Open_Face; it simply specifies |
| * the font driver to use for opening the face. If set to `NULL`, |
| * FreeType tries to load the face with each one of the drivers in its |
| * list. |
| * |
| * num_params :: |
| * The number of extra parameters. |
| * |
| * params :: |
| * Extra parameters passed to the font driver when opening a new face. |
| * |
| * @note: |
| * The stream type is determined by the contents of `flags`: |
| * |
| * If the @FT_OPEN_MEMORY bit is set, assume that this is a memory file |
| * of `memory_size` bytes, located at `memory_address`. The data are not |
| * copied, and the client is responsible for releasing and destroying |
| * them _after_ the corresponding call to @FT_Done_Face. |
| * |
| * Otherwise, if the @FT_OPEN_STREAM bit is set, assume that a custom |
| * input stream `stream` is used. |
| * |
| * Otherwise, if the @FT_OPEN_PATHNAME bit is set, assume that this is a |
| * normal file and use `pathname` to open it. |
| * |
| * If none of the above bits are set or if multiple are set at the same |
| * time, the flags are invalid and @FT_Open_Face fails. |
| * |
| * If the @FT_OPEN_DRIVER bit is set, @FT_Open_Face only tries to open |
| * the file with the driver whose handler is in `driver`. |
| * |
| * If the @FT_OPEN_PARAMS bit is set, the parameters given by |
| * `num_params` and `params` is used. They are ignored otherwise. |
| * |
| * Ideally, both the `pathname` and `params` fields should be tagged as |
| * 'const'; this is missing for API backward compatibility. In other |
| * words, applications should treat them as read-only. |
| */ |
| typedef struct FT_Open_Args_ |
| { |
| FT_UInt flags; |
| const FT_Byte* memory_base; |
| FT_Long memory_size; |
| FT_String* pathname; |
| FT_Stream stream; |
| FT_Module driver; |
| FT_Int num_params; |
| FT_Parameter* params; |
| |
| } FT_Open_Args; |
| |
| |
| /************************************************************************** |
| * |
| * @function: |
| * FT_New_Face |
| * |
| * @description: |
| * Call @FT_Open_Face to open a font by its pathname. |
| * |
| * @inout: |
| * library :: |
| * A handle to the library resource. |
| * |
| * @input: |
| * pathname :: |
| * A path to the font file. |
| * |
| * face_index :: |
| * See @FT_Open_Face for a detailed description of this parameter. |
| * |
| * @output: |
| * aface :: |
| * A handle to a new face object. If `face_index` is greater than or |
| * equal to zero, it must be non-`NULL`. |
| * |
| * @return: |
| * FreeType error code. 0~means success. |
| * |
| * @note: |
| * The `pathname` string should be recognizable as such by a standard |
| * `fopen` call on your system; in particular, this means that `pathname` |
| * must not contain null bytes. If that is not sufficient to address all |
| * file name possibilities (for example, to handle wide character file |
| * names on Windows in UTF-16 encoding) you might use @FT_Open_Face to |
| * pass a memory array or a stream object instead. |
| * |
| * Use @FT_Done_Face to destroy the created @FT_Face object (along with |
| * its slot and sizes). |
| */ |
| FT_EXPORT( FT_Error ) |
| FT_New_Face( FT_Library library, |
| const char* filepathname, |
| FT_Long face_index, |
| FT_Face *aface ); |
| |
| |
| /************************************************************************** |
| * |
| * @function: |
| * FT_New_Memory_Face |
| * |
| * @description: |
| * Call @FT_Open_Face to open a font that has been loaded into memory. |
| * |
| * @inout: |
| * library :: |
| * A handle to the library resource. |
| * |
| * @input: |
| * file_base :: |
| * A pointer to the beginning of the font data. |
| * |
| * file_size :: |
| * The size of the memory chunk used by the font data. |
| * |
| * face_index :: |
| * See @FT_Open_Face for a detailed description of this parameter. |
| * |
| * @output: |
| * aface :: |
| * A handle to a new face object. If `face_index` is greater than or |
| * equal to zero, it must be non-`NULL`. |
| * |
| * @return: |
| * FreeType error code. 0~means success. |
| * |
| * @note: |
| * You must not deallocate the memory before calling @FT_Done_Face. |
| */ |
| FT_EXPORT( FT_Error ) |
| FT_New_Memory_Face( FT_Library library, |
| const FT_Byte* file_base, |
| FT_Long file_size, |
| FT_Long face_index, |
| FT_Face *aface ); |
| |
| |
| /************************************************************************** |
| * |
| * @function: |
| * FT_Open_Face |
| * |
| * @description: |
| * Create a face object from a given resource described by @FT_Open_Args. |
| * |
| * @inout: |
| * library :: |
| * A handle to the library resource. |
| * |
| * @input: |
| * args :: |
| * A pointer to an `FT_Open_Args` structure that must be filled by the |
| * caller. |
| * |
| * face_index :: |
| * This field holds two different values. Bits 0-15 are the index of |
| * the face in the font file (starting with value~0). Set it to~0 if |
| * there is only one face in the font file. |
| * |
| * [Since 2.6.1] Bits 16-30 are relevant to GX and OpenType variation |
| * fonts only, specifying the named instance index for the current face |
| * index (starting with value~1; value~0 makes FreeType ignore named |
| * instances). For non-variation fonts, bits 16-30 are ignored. |
| * Assuming that you want to access the third named instance in face~4, |
| * `face_index` should be set to 0x00030004. If you want to access |
| * face~4 without variation handling, simply set `face_index` to |
| * value~4. |
| * |
| * `FT_Open_Face` and its siblings can be used to quickly check whether |
| * the font format of a given font resource is supported by FreeType. |
| * In general, if the `face_index` argument is negative, the function's |
| * return value is~0 if the font format is recognized, or non-zero |
| * otherwise. The function allocates a more or less empty face handle |
| * in `*aface` (if `aface` isn't `NULL`); the only two useful fields in |
| * this special case are `face->num_faces` and `face->style_flags`. |
| * For any negative value of `face_index`, `face->num_faces` gives the |
| * number of faces within the font file. For the negative value |
| * '-(N+1)' (with 'N' a non-negative 16-bit value), bits 16-30 in |
| * `face->style_flags` give the number of named instances in face 'N' |
| * if we have a variation font (or zero otherwise). After examination, |
| * the returned @FT_Face structure should be deallocated with a call to |
| * @FT_Done_Face. |
| * |
| * @output: |
| * aface :: |
| * A handle to a new face object. If `face_index` is greater than or |
| * equal to zero, it must be non-`NULL`. |
| * |
| * @return: |
| * FreeType error code. 0~means success. |
| * |
| * @note: |
| * Unlike FreeType 1.x, this function automatically creates a glyph slot |
| * for the face object that can be accessed directly through |
| * `face->glyph`. |
| * |
| * Each new face object created with this function also owns a default |
| * @FT_Size object, accessible as `face->size`. |
| * |
| * One @FT_Library instance can have multiple face objects, this is, |
| * @FT_Open_Face and its siblings can be called multiple times using the |
| * same `library` argument. |
| * |
| * See the discussion of reference counters in the description of |
| * @FT_Reference_Face. |
| * |
| * If `FT_OPEN_STREAM` is set in `args->flags`, the stream in |
| * `args->stream` is automatically closed before this function returns |
| * any error (including `FT_Err_Invalid_Argument`). |
| * |
| * @example: |
| * To loop over all faces, use code similar to the following snippet |
| * (omitting the error handling). |
| * |
| * ``` |
| * ... |
| * FT_Face face; |
| * FT_Long i, num_faces; |
| * |
| * |
| * error = FT_Open_Face( library, args, -1, &face ); |
| * if ( error ) { ... } |
| * |
| * num_faces = face->num_faces; |
| * FT_Done_Face( face ); |
| * |
| * for ( i = 0; i < num_faces; i++ ) |
| * { |
| * ... |
| * error = FT_Open_Face( library, args, i, &face ); |
| * ... |
| * FT_Done_Face( face ); |
| * ... |
| * } |
| * ``` |
| * |
| * To loop over all valid values for `face_index`, use something similar |
| * to the following snippet, again without error handling. The code |
| * accesses all faces immediately (thus only a single call of |
| * `FT_Open_Face` within the do-loop), with and without named instances. |
| * |
| * ``` |
| * ... |
| * FT_Face face; |
| * |
| * FT_Long num_faces = 0; |
| * FT_Long num_instances = 0; |
| * |
| * FT_Long face_idx = 0; |
| * FT_Long instance_idx = 0; |
| * |
| * |
| * do |
| * { |
| * FT_Long id = ( instance_idx << 16 ) + face_idx; |
| * |
| * |
| * error = FT_Open_Face( library, args, id, &face ); |
| * if ( error ) { ... } |
| * |
| * num_faces = face->num_faces; |
| * num_instances = face->style_flags >> 16; |
| * |
| * ... |
| * |
| * FT_Done_Face( face ); |
| * |
| * if ( instance_idx < num_instances ) |
| * instance_idx++; |
| * else |
| * { |
| * face_idx++; |
| * instance_idx = 0; |
| * } |
| * |
| * } while ( face_idx < num_faces ) |
| * ``` |
| */ |
| FT_EXPORT( FT_Error ) |
| FT_Open_Face( FT_Library library, |
| const FT_Open_Args* args, |
| FT_Long face_index, |
| FT_Face *aface ); |
| |
| |
| /************************************************************************** |
| * |
| * @function: |
| * FT_Attach_File |
| * |
| * @description: |
| * Call @FT_Attach_Stream to attach a file. |
| * |
| * @inout: |
| * face :: |
| * The target face object. |
| * |
| * @input: |
| * filepathname :: |
| * The pathname. |
| * |
| * @return: |
| * FreeType error code. 0~means success. |
| */ |
| FT_EXPORT( FT_Error ) |
| FT_Attach_File( FT_Face face, |
| const char* filepathname ); |
| |
| |
| /************************************************************************** |
| * |
| * @function: |
| * FT_Attach_Stream |
| * |
| * @description: |
| * 'Attach' data to a face object. Normally, this is used to read |
| * additional information for the face object. For example, you can |
| * attach an AFM file that comes with a Type~1 font to get the kerning |
| * values and other metrics. |
| * |
| * @inout: |
| * face :: |
| * The target face object. |
| * |
| * @input: |
| * parameters :: |
| * A pointer to @FT_Open_Args that must be filled by the caller. |
| * |
| * @return: |
| * FreeType error code. 0~means success. |
| * |
| * @note: |
| * The meaning of the 'attach' (i.e., what really happens when the new |
| * file is read) is not fixed by FreeType itself. It really depends on |
| * the font format (and thus the font driver). |
| * |
| * Client applications are expected to know what they are doing when |
| * invoking this function. Most drivers simply do not implement file or |
| * stream attachments. |
| */ |
| FT_EXPORT( FT_Error ) |
| FT_Attach_Stream( FT_Face face, |
| const FT_Open_Args* parameters ); |
| |
| |
| /************************************************************************** |
| * |
| * @function: |
| * FT_Reference_Face |
| * |
| * @description: |
| * A counter gets initialized to~1 at the time an @FT_Face structure is |
| * created. This function increments the counter. @FT_Done_Face then |
| * only destroys a face if the counter is~1, otherwise it simply |
| * decrements the counter. |
| * |
| * This function helps in managing life-cycles of structures that |
| * reference @FT_Face objects. |
| * |
| * @input: |
| * face :: |
| * A handle to a target face object. |
| * |
| * @return: |
| * FreeType error code. 0~means success. |
| * |
| * @since: |
| * 2.4.2 |
| * |
| */ |
| FT_EXPORT( FT_Error ) |
| FT_Reference_Face( FT_Face face ); |
| |
| |
| /************************************************************************** |
| * |
| * @function: |
| * FT_Done_Face |
| * |
| * @description: |
| * Discard a given face object, as well as all of its child slots and |
| * sizes. |
| * |
| * @input: |
| * face :: |
| * A handle to a target face object. |
| * |
| * @return: |
| * FreeType error code. 0~means success. |
| * |
| * @note: |
| * See the discussion of reference counters in the description of |
| * @FT_Reference_Face. |
| */ |
| FT_EXPORT( FT_Error ) |
| FT_Done_Face( FT_Face face ); |
| |
| |
| /************************************************************************** |
| * |
| * @function: |
| * FT_Select_Size |
| * |
| * @description: |
| * Select a bitmap strike. To be more precise, this function sets the |
| * scaling factors of the active @FT_Size object in a face so that |
| * bitmaps from this particular strike are taken by @FT_Load_Glyph and |
| * friends. |
| * |
| * @inout: |
| * face :: |
| * A handle to a target face object. |
| * |
| * @input: |
| * strike_index :: |
| * The index of the bitmap strike in the `available_sizes` field of |
| * @FT_FaceRec structure. |
| * |
| * @return: |
| * FreeType error code. 0~means success. |
| * |
| * @note: |
| * For bitmaps embedded in outline fonts it is common that only a subset |
| * of the available glyphs at a given ppem value is available. FreeType |
| * silently uses outlines if there is no bitmap for a given glyph index. |
| * |
| * For GX and OpenType variation fonts, a bitmap strike makes sense only |
| * if the default instance is active (this is, no glyph variation takes |
| * place); otherwise, FreeType simply ignores bitmap strikes. The same |
| * is true for all named instances that are different from the default |
| * instance. |
| * |
| * Don't use this function if you are using the FreeType cache API. |
| */ |
| FT_EXPORT( FT_Error ) |
| FT_Select_Size( FT_Face face, |
| FT_Int strike_index ); |
| |
| |
| /************************************************************************** |
| * |
| * @enum: |
| * FT_Size_Request_Type |
| * |
| * @description: |
| * An enumeration type that lists the supported size request types, i.e., |
| * what input size (in font units) maps to the requested output size (in |
| * pixels, as computed from the arguments of @FT_Size_Request). |
| * |
| * @values: |
| * FT_SIZE_REQUEST_TYPE_NOMINAL :: |
| * The nominal size. The `units_per_EM` field of @FT_FaceRec is used |
| * to determine both scaling values. |
| * |
| * This is the standard scaling found in most applications. In |
| * particular, use this size request type for TrueType fonts if they |
| * provide optical scaling or something similar. Note, however, that |
| * `units_per_EM` is a rather abstract value which bears no relation to |
| * the actual size of the glyphs in a font. |
| * |
| * FT_SIZE_REQUEST_TYPE_REAL_DIM :: |
| * The real dimension. The sum of the `ascender` and (minus of) the |
| * `descender` fields of @FT_FaceRec is used to determine both scaling |
| * values. |
| * |
| * FT_SIZE_REQUEST_TYPE_BBOX :: |
| * The font bounding box. The width and height of the `bbox` field of |
| * @FT_FaceRec are used to determine the horizontal and vertical |
| * scaling value, respectively. |
| * |
| * FT_SIZE_REQUEST_TYPE_CELL :: |
| * The `max_advance_width` field of @FT_FaceRec is used to determine |
| * the horizontal scaling value; the vertical scaling value is |
| * determined the same way as @FT_SIZE_REQUEST_TYPE_REAL_DIM does. |
| * Finally, both scaling values are set to the smaller one. This type |
| * is useful if you want to specify the font size for, say, a window of |
| * a given dimension and 80x24 cells. |
| * |
| * FT_SIZE_REQUEST_TYPE_SCALES :: |
| * Specify the scaling values directly. |
| * |
| * @note: |
| * The above descriptions only apply to scalable formats. For bitmap |
| * formats, the behaviour is up to the driver. |
| * |
| * See the note section of @FT_Size_Metrics if you wonder how size |
| * requesting relates to scaling values. |
| */ |
| typedef enum FT_Size_Request_Type_ |
| { |
| FT_SIZE_REQUEST_TYPE_NOMINAL, |
| FT_SIZE_REQUEST_TYPE_REAL_DIM, |
| FT_SIZE_REQUEST_TYPE_BBOX, |
| FT_SIZE_REQUEST_TYPE_CELL, |
| FT_SIZE_REQUEST_TYPE_SCALES, |
| |
| FT_SIZE_REQUEST_TYPE_MAX |
| |
| } FT_Size_Request_Type; |
| |
| |
| /************************************************************************** |
| * |
| * @struct: |
| * FT_Size_RequestRec |
| * |
| * @description: |
| * A structure to model a size request. |
| * |
| * @fields: |
| * type :: |
| * See @FT_Size_Request_Type. |
| * |
| * width :: |
| * The desired width, given as a 26.6 fractional point value (with 72pt |
| * = 1in). |
| * |
| * height :: |
| * The desired height, given as a 26.6 fractional point value (with |
| * 72pt = 1in). |
| * |
| * horiResolution :: |
| * The horizontal resolution (dpi, i.e., pixels per inch). If set to |
| * zero, `width` is treated as a 26.6 fractional **pixel** value, which |
| * gets internally rounded to an integer. |
| * |
| * vertResolution :: |
| * The vertical resolution (dpi, i.e., pixels per inch). If set to |
| * zero, `height` is treated as a 26.6 fractional **pixel** value, |
| * which gets internally rounded to an integer. |
| * |
| * @note: |
| * If `width` is zero, the horizontal scaling value is set equal to the |
| * vertical scaling value, and vice versa. |
| * |
| * If `type` is `FT_SIZE_REQUEST_TYPE_SCALES`, `width` and `height` are |
| * interpreted directly as 16.16 fractional scaling values, without any |
| * further modification, and both `horiResolution` and `vertResolution` |
| * are ignored. |
| */ |
| typedef struct FT_Size_RequestRec_ |
| { |
| FT_Size_Request_Type type; |
| FT_Long width; |
| FT_Long height; |
| FT_UInt horiResolution; |
| FT_UInt vertResolution; |
| |
| } FT_Size_RequestRec; |
| |
| |
| /************************************************************************** |
| * |
| * @struct: |
| * FT_Size_Request |
| * |
| * @description: |
| * A handle to a size request structure. |
| */ |
| typedef struct FT_Size_RequestRec_ *FT_Size_Request; |
| |
| |
| /************************************************************************** |
| * |
| * @function: |
| * FT_Request_Size |
| * |
| * @description: |
| * Resize the scale of the active @FT_Size object in a face. |
| * |
| * @inout: |
| * face :: |
| * A handle to a target face object. |
| * |
| * @input: |
| * req :: |
| * A pointer to a @FT_Size_RequestRec. |
| * |
| * @return: |
| * FreeType error code. 0~means success. |
| * |
| * @note: |
| * Although drivers may select the bitmap strike matching the request, |
| * you should not rely on this if you intend to select a particular |
| * bitmap strike. Use @FT_Select_Size instead in that case. |
| * |
| * The relation between the requested size and the resulting glyph size |
| * is dependent entirely on how the size is defined in the source face. |
| * The font designer chooses the final size of each glyph relative to |
| * this size. For more information refer to |
| * 'https://www.freetype.org/freetype2/docs/glyphs/glyphs-2.html'. |
| * |
| * Contrary to @FT_Set_Char_Size, this function doesn't have special code |
| * to normalize zero-valued widths, heights, or resolutions, which are |
| * treated as @FT_LOAD_NO_SCALE. |
| * |
| * Don't use this function if you are using the FreeType cache API. |
| */ |
| FT_EXPORT( FT_Error ) |
| FT_Request_Size( FT_Face face, |
| FT_Size_Request req ); |
| |
| |
| /************************************************************************** |
| * |
| * @function: |
| * FT_Set_Char_Size |
| * |
| * @description: |
| * Call @FT_Request_Size to request the nominal size (in points). |
| * |
| * @inout: |
| * face :: |
| * A handle to a target face object. |
| * |
| * @input: |
| * char_width :: |
| * The nominal width, in 26.6 fractional points. |
| * |
| * char_height :: |
| * The nominal height, in 26.6 fractional points. |
| * |
| * horz_resolution :: |
| * The horizontal resolution in dpi. |
| * |
| * vert_resolution :: |
| * The vertical resolution in dpi. |
| * |
| * @return: |
| * FreeType error code. 0~means success. |
| * |
| * @note: |
| * While this function allows fractional points as input values, the |
| * resulting ppem value for the given resolution is always rounded to the |
| * nearest integer. |
| * |
| * If either the character width or height is zero, it is set equal to |
| * the other value. |
| * |
| * If either the horizontal or vertical resolution is zero, it is set |
| * equal to the other value. |
| * |
| * A character width or height smaller than 1pt is set to 1pt; if both |
| * resolution values are zero, they are set to 72dpi. |
| * |
| * Don't use this function if you are using the FreeType cache API. |
| */ |
| FT_EXPORT( FT_Error ) |
| FT_Set_Char_Size( FT_Face face, |
| FT_F26Dot6 char_width, |
| FT_F26Dot6 char_height, |
| FT_UInt horz_resolution, |
| FT_UInt vert_resolution ); |
| |
| |
| /************************************************************************** |
| * |
| * @function: |
| * FT_Set_Pixel_Sizes |
| * |
| * @description: |
| * Call @FT_Request_Size to request the nominal size (in pixels). |
| * |
| * @inout: |
| * face :: |
| * A handle to the target face object. |
| * |
| * @input: |
| * pixel_width :: |
| * The nominal width, in pixels. |
| * |
| * pixel_height :: |
| * The nominal height, in pixels. |
| * |
| * @return: |
| * FreeType error code. 0~means success. |
| * |
| * @note: |
| * You should not rely on the resulting glyphs matching or being |
| * constrained to this pixel size. Refer to @FT_Request_Size to |
| * understand how requested sizes relate to actual sizes. |
| * |
| * Don't use this function if you are using the FreeType cache API. |
| */ |
| FT_EXPORT( FT_Error ) |
| FT_Set_Pixel_Sizes( FT_Face face, |
| FT_UInt pixel_width, |
| FT_UInt pixel_height ); |
| |
| |
| /************************************************************************** |
| * |
| * @function: |
| * FT_Load_Glyph |
| * |
| * @description: |
| * Load a glyph into the glyph slot of a face object. |
| * |
| * @inout: |
| * face :: |
| * A handle to the target face object where the glyph is loaded. |
| * |
| * @input: |
| * glyph_index :: |
| * The index of the glyph in the font file. For CID-keyed fonts |
| * (either in PS or in CFF format) this argument specifies the CID |
| * value. |
| * |
| * load_flags :: |
| * A flag indicating what to load for this glyph. The @FT_LOAD_XXX |
| * flags can be used to control the glyph loading process (e.g., |
| * whether the outline should be scaled, whether to load bitmaps or |
| * not, whether to hint the outline, etc). |
| * |
| * @return: |
| * FreeType error code. 0~means success. |
| * |
| * @note: |
| * For proper scaling and hinting, the active @FT_Size object owned by |
| * the face has to be meaningfully initialized by calling |
| * @FT_Set_Char_Size before this function, for example. The loaded |
| * glyph may be transformed. See @FT_Set_Transform for the details. |
| * |
| * For subsetted CID-keyed fonts, `FT_Err_Invalid_Argument` is returned |
| * for invalid CID values (this is, for CID values that don't have a |
| * corresponding glyph in the font). See the discussion of the |
| * @FT_FACE_FLAG_CID_KEYED flag for more details. |
| * |
| * If you receive `FT_Err_Glyph_Too_Big`, try getting the glyph outline |
| * at EM size, then scale it manually and fill it as a graphics |
| * operation. |
| */ |
| FT_EXPORT( FT_Error ) |
| FT_Load_Glyph( FT_Face face, |
| FT_UInt glyph_index, |
| FT_Int32 load_flags ); |
| |
| |
| /************************************************************************** |
| * |
| * @function: |
| * FT_Load_Char |
| * |
| * @description: |
| * Load a glyph into the glyph slot of a face object, accessed by its |
| * character code. |
| * |
| * @inout: |
| * face :: |
| * A handle to a target face object where the glyph is loaded. |
| * |
| * @input: |
| * char_code :: |
| * The glyph's character code, according to the current charmap used in |
| * the face. |
| * |
| * load_flags :: |
| * A flag indicating what to load for this glyph. The @FT_LOAD_XXX |
| * constants can be used to control the glyph loading process (e.g., |
| * whether the outline should be scaled, whether to load bitmaps or |
| * not, whether to hint the outline, etc). |
| * |
| * @return: |
| * FreeType error code. 0~means success. |
| * |
| * @note: |
| * This function simply calls @FT_Get_Char_Index and @FT_Load_Glyph. |
| * |
| * Many fonts contain glyphs that can't be loaded by this function since |
| * its glyph indices are not listed in any of the font's charmaps. |
| * |
| * If no active cmap is set up (i.e., `face->charmap` is zero), the call |
| * to @FT_Get_Char_Index is omitted, and the function behaves identically |
| * to @FT_Load_Glyph. |
| */ |
| FT_EXPORT( FT_Error ) |
| FT_Load_Char( FT_Face face, |
| FT_ULong char_code, |
| FT_Int32 load_flags ); |
| |
| |
| /************************************************************************** |
| * |
| * @enum: |
| * FT_LOAD_XXX |
| * |
| * @description: |
| * A list of bit field constants for @FT_Load_Glyph to indicate what kind |
| * of operations to perform during glyph loading. |
| * |
| * @values: |
| * FT_LOAD_DEFAULT :: |
| * Corresponding to~0, this value is used as the default glyph load |
| * operation. In this case, the following happens: |
| * |
| * 1. FreeType looks for a bitmap for the glyph corresponding to the |
| * face's current size. If one is found, the function returns. The |
| * bitmap data can be accessed from the glyph slot (see note below). |
| * |
| * 2. If no embedded bitmap is searched for or found, FreeType looks |
| * for a scalable outline. If one is found, it is loaded from the font |
| * file, scaled to device pixels, then 'hinted' to the pixel grid in |
| * order to optimize it. The outline data can be accessed from the |
| * glyph slot (see note below). |
| * |
| * Note that by default the glyph loader doesn't render outlines into |
| * bitmaps. The following flags are used to modify this default |
| * behaviour to more specific and useful cases. |
| * |
| * FT_LOAD_NO_SCALE :: |
| * Don't scale the loaded outline glyph but keep it in font units. |
| * This flag is also assumed if @FT_Size owned by the face was not |
| * properly initialized. |
| * |
| * This flag implies @FT_LOAD_NO_HINTING and @FT_LOAD_NO_BITMAP, and |
| * unsets @FT_LOAD_RENDER. |
| * |
| * If the font is 'tricky' (see @FT_FACE_FLAG_TRICKY for more), using |
| * `FT_LOAD_NO_SCALE` usually yields meaningless outlines because the |
| * subglyphs must be scaled and positioned with hinting instructions. |
| * This can be solved by loading the font without `FT_LOAD_NO_SCALE` |
| * and setting the character size to `font->units_per_EM`. |
| * |
| * FT_LOAD_NO_HINTING :: |
| * Disable hinting. This generally generates 'blurrier' bitmap glyphs |
| * when the glyphs are rendered in any of the anti-aliased modes. See |
| * also the note below. |
| * |
| * This flag is implied by @FT_LOAD_NO_SCALE. |
| * |
| * FT_LOAD_RENDER :: |
| * Call @FT_Render_Glyph after the glyph is loaded. By default, the |
| * glyph is rendered in @FT_RENDER_MODE_NORMAL mode. This can be |
| * overridden by @FT_LOAD_TARGET_XXX or @FT_LOAD_MONOCHROME. |
| * |
| * This flag is unset by @FT_LOAD_NO_SCALE. |
| * |
| * FT_LOAD_NO_BITMAP :: |
| * Ignore bitmap strikes when loading. Bitmap-only fonts ignore this |
| * flag. |
| * |
| * @FT_LOAD_NO_SCALE always sets this flag. |
| * |
| * FT_LOAD_SBITS_ONLY :: |
| * [Since 2.12] This is the opposite of @FT_LOAD_NO_BITMAP, more or |
| * less: @FT_Load_Glyph returns `FT_Err_Invalid_Argument` if the face |
| * contains a bitmap strike for the given size (or the strike selected |
| * by @FT_Select_Size) but there is no glyph in the strike. |
| * |
| * Note that this load flag was part of FreeType since version 2.0.6 |
| * but previously tagged as internal. |
| * |
| * FT_LOAD_VERTICAL_LAYOUT :: |
| * Load the glyph for vertical text layout. In particular, the |
| * `advance` value in the @FT_GlyphSlotRec structure is set to the |
| * `vertAdvance` value of the `metrics` field. |
| * |
| * In case @FT_HAS_VERTICAL doesn't return true, you shouldn't use this |
| * flag currently. Reason is that in this case vertical metrics get |
| * synthesized, and those values are not always consistent across |
| * various font formats. |
| * |
| * FT_LOAD_FORCE_AUTOHINT :: |
| * Prefer the auto-hinter over the font's native hinter. See also the |
| * note below. |
| * |
| * FT_LOAD_PEDANTIC :: |
| * Make the font driver perform pedantic verifications during glyph |
| * loading and hinting. This is mostly used to detect broken glyphs in |
| * fonts. By default, FreeType tries to handle broken fonts also. |
| * |
| * In particular, errors from the TrueType bytecode engine are not |
| * passed to the application if this flag is not set; this might result |
| * in partially hinted or distorted glyphs in case a glyph's bytecode |
| * is buggy. |
| * |
| * FT_LOAD_NO_RECURSE :: |
| * Don't load composite glyphs recursively. Instead, the font driver |
| * fills the `num_subglyph` and `subglyphs` values of the glyph slot; |
| * it also sets `glyph->format` to @FT_GLYPH_FORMAT_COMPOSITE. The |
| * description of subglyphs can then be accessed with |
| * @FT_Get_SubGlyph_Info. |
| * |
| * Don't use this flag for retrieving metrics information since some |
| * font drivers only return rudimentary data. |
| * |
| * This flag implies @FT_LOAD_NO_SCALE and @FT_LOAD_IGNORE_TRANSFORM. |
| * |
| * FT_LOAD_IGNORE_TRANSFORM :: |
| * Ignore the transform matrix set by @FT_Set_Transform. |
| * |
| * FT_LOAD_MONOCHROME :: |
| * This flag is used with @FT_LOAD_RENDER to indicate that you want to |
| * render an outline glyph to a 1-bit monochrome bitmap glyph, with |
| * 8~pixels packed into each byte of the bitmap data. |
| * |
| * Note that this has no effect on the hinting algorithm used. You |
| * should rather use @FT_LOAD_TARGET_MONO so that the |
| * monochrome-optimized hinting algorithm is used. |
| * |
| * FT_LOAD_LINEAR_DESIGN :: |
| * Keep `linearHoriAdvance` and `linearVertAdvance` fields of |
| * @FT_GlyphSlotRec in font units. See @FT_GlyphSlotRec for details. |
| * |
| * FT_LOAD_NO_AUTOHINT :: |
| * Disable the auto-hinter. See also the note below. |
| * |
| * FT_LOAD_COLOR :: |
| * Load colored glyphs. FreeType searches in the following order; |
| * there are slight differences depending on the font format. |
| * |
| * [Since 2.5] Load embedded color bitmap images (provided |
| * @FT_LOAD_NO_BITMAP is not set). The resulting color bitmaps, if |
| * available, have the @FT_PIXEL_MODE_BGRA format, with pre-multiplied |
| * color channels. If the flag is not set and color bitmaps are found, |
| * they are converted to 256-level gray bitmaps, using the |
| * @FT_PIXEL_MODE_GRAY format. |
| * |
| * [Since 2.12] If the glyph index maps to an entry in the face's |
| * 'SVG~' table, load the associated SVG document from this table and |
| * set the `format` field of @FT_GlyphSlotRec to @FT_GLYPH_FORMAT_SVG. |
| * Note that FreeType itself can't render SVG documents; however, the |
| * library provides hooks to seamlessly integrate an external renderer. |
| * See sections @ot_svg_driver and @svg_fonts for more. |
| * |
| * [Since 2.10, experimental] If the glyph index maps to an entry in |
| * the face's 'COLR' table with a 'CPAL' palette table (as defined in |
| * the OpenType specification), make @FT_Render_Glyph provide a default |
| * blending of the color glyph layers associated with the glyph index, |
| * using the same bitmap format as embedded color bitmap images. This |
| * is mainly for convenience and works only for glyphs in 'COLR' v0 |
| * tables (or glyphs in 'COLR' v1 tables that exclusively use v0 |
| * features). For full control of color layers use |
| * @FT_Get_Color_Glyph_Layer and FreeType's color functions like |
| * @FT_Palette_Select instead of setting @FT_LOAD_COLOR for rendering |
| * so that the client application can handle blending by itself. |
| * |
| * FT_LOAD_COMPUTE_METRICS :: |
| * [Since 2.6.1] Compute glyph metrics from the glyph data, without the |
| * use of bundled metrics tables (for example, the 'hdmx' table in |
| * TrueType fonts). This flag is mainly used by font validating or |
| * font editing applications, which need to ignore, verify, or edit |
| * those tables. |
| * |
| * Currently, this flag is only implemented for TrueType fonts. |
| * |
| * FT_LOAD_BITMAP_METRICS_ONLY :: |
| * [Since 2.7.1] Request loading of the metrics and bitmap image |
| * information of a (possibly embedded) bitmap glyph without allocating |
| * or copying the bitmap image data itself. No effect if the target |
| * glyph is not a bitmap image. |
| * |
| * This flag unsets @FT_LOAD_RENDER. |
| * |
| * FT_LOAD_CROP_BITMAP :: |
| * Ignored. Deprecated. |
| * |
| * FT_LOAD_IGNORE_GLOBAL_ADVANCE_WIDTH :: |
| * Ignored. Deprecated. |
| * |
| * @note: |
| * By default, hinting is enabled and the font's native hinter (see |
| * @FT_FACE_FLAG_HINTER) is preferred over the auto-hinter. You can |
| * disable hinting by setting @FT_LOAD_NO_HINTING or change the |
| * precedence by setting @FT_LOAD_FORCE_AUTOHINT. You can also set |
| * @FT_LOAD_NO_AUTOHINT in case you don't want the auto-hinter to be used |
| * at all. |
| * |
| * See the description of @FT_FACE_FLAG_TRICKY for a special exception |
| * (affecting only a handful of Asian fonts). |
| * |
| * Besides deciding which hinter to use, you can also decide which |
| * hinting algorithm to use. See @FT_LOAD_TARGET_XXX for details. |
| * |
| * Note that the auto-hinter needs a valid Unicode cmap (either a native |
| * one or synthesized by FreeType) for producing correct results. If a |
| * font provides an incorrect mapping (for example, assigning the |
| * character code U+005A, LATIN CAPITAL LETTER~Z, to a glyph depicting a |
| * mathematical integral sign), the auto-hinter might produce useless |
| * results. |
| * |
| */ |
| #define FT_LOAD_DEFAULT 0x0 |
| #define FT_LOAD_NO_SCALE ( 1L << 0 ) |
| #define FT_LOAD_NO_HINTING ( 1L << 1 ) |
| #define FT_LOAD_RENDER ( 1L << 2 ) |
| #define FT_LOAD_NO_BITMAP ( 1L << 3 ) |
| #define FT_LOAD_VERTICAL_LAYOUT ( 1L << 4 ) |
| #define FT_LOAD_FORCE_AUTOHINT ( 1L << 5 ) |
| #define FT_LOAD_CROP_BITMAP ( 1L << 6 ) |
| #define FT_LOAD_PEDANTIC ( 1L << 7 ) |
| #define FT_LOAD_IGNORE_GLOBAL_ADVANCE_WIDTH ( 1L << 9 ) |
| #define FT_LOAD_NO_RECURSE ( 1L << 10 ) |
| #define FT_LOAD_IGNORE_TRANSFORM ( 1L << 11 ) |
| #define FT_LOAD_MONOCHROME ( 1L << 12 ) |
| #define FT_LOAD_LINEAR_DESIGN ( 1L << 13 ) |
| #define FT_LOAD_SBITS_ONLY ( 1L << 14 ) |
| #define FT_LOAD_NO_AUTOHINT ( 1L << 15 ) |
| /* Bits 16-19 are used by `FT_LOAD_TARGET_` */ |
| #define FT_LOAD_COLOR ( 1L << 20 ) |
| #define FT_LOAD_COMPUTE_METRICS ( 1L << 21 ) |
| #define FT_LOAD_BITMAP_METRICS_ONLY ( 1L << 22 ) |
| |
| /* */ |
| |
| /* used internally only by certain font drivers */ |
| #define FT_LOAD_ADVANCE_ONLY ( 1L << 8 ) |
| #define FT_LOAD_SVG_ONLY ( 1L << 23 ) |
| |
| |
| /************************************************************************** |
| * |
| * @enum: |
| * FT_LOAD_TARGET_XXX |
| * |
| * @description: |
| * A list of values to select a specific hinting algorithm for the |
| * hinter. You should OR one of these values to your `load_flags` when |
| * calling @FT_Load_Glyph. |
| * |
| * Note that a font's native hinters may ignore the hinting algorithm you |
| * have specified (e.g., the TrueType bytecode interpreter). You can set |
| * @FT_LOAD_FORCE_AUTOHINT to ensure that the auto-hinter is used. |
| * |
| * @values: |
| * FT_LOAD_TARGET_NORMAL :: |
| * The default hinting algorithm, optimized for standard gray-level |
| * rendering. For monochrome output, use @FT_LOAD_TARGET_MONO instead. |
| * |
| * FT_LOAD_TARGET_LIGHT :: |
| * A lighter hinting algorithm for gray-level modes. Many generated |
| * glyphs are fuzzier but better resemble their original shape. This |
| * is achieved by snapping glyphs to the pixel grid only vertically |
| * (Y-axis), as is done by FreeType's new CFF engine or Microsoft's |
| * ClearType font renderer. This preserves inter-glyph spacing in |
| * horizontal text. The snapping is done either by the native font |
| * driver, if the driver itself and the font support it, or by the |
| * auto-hinter. |
| * |
| * Advance widths are rounded to integer values; however, using the |
| * `lsb_delta` and `rsb_delta` fields of @FT_GlyphSlotRec, it is |
| * possible to get fractional advance widths for subpixel positioning |
| * (which is recommended to use). |
| * |
| * If configuration option `AF_CONFIG_OPTION_TT_SIZE_METRICS` is |
| * active, TrueType-like metrics are used to make this mode behave |
| * similarly as in unpatched FreeType versions between 2.4.6 and 2.7.1 |
| * (inclusive). |
| * |
| * FT_LOAD_TARGET_MONO :: |
| * Strong hinting algorithm that should only be used for monochrome |
| * output. The result is probably unpleasant if the glyph is rendered |
| * in non-monochrome modes. |
| * |
| * Note that for outline fonts only the TrueType font driver has proper |
| * monochrome hinting support, provided the TTFs contain hints for B/W |
| * rendering (which most fonts no longer provide). If these conditions |
| * are not met it is very likely that you get ugly results at smaller |
| * sizes. |
| * |
| * FT_LOAD_TARGET_LCD :: |
| * A variant of @FT_LOAD_TARGET_LIGHT optimized for horizontally |
| * decimated LCD displays. |
| * |
| * FT_LOAD_TARGET_LCD_V :: |
| * A variant of @FT_LOAD_TARGET_NORMAL optimized for vertically |
| * decimated LCD displays. |
| * |
| * @note: |
| * You should use only _one_ of the `FT_LOAD_TARGET_XXX` values in your |
| * `load_flags`. They can't be ORed. |
| * |
| * If @FT_LOAD_RENDER is also set, the glyph is rendered in the |
| * corresponding mode (i.e., the mode that matches the used algorithm |
| * best). An exception is `FT_LOAD_TARGET_MONO` since it implies |
| * @FT_LOAD_MONOCHROME. |
| * |
| * You can use a hinting algorithm that doesn't correspond to the same |
| * rendering mode. As an example, it is possible to use the 'light' |
| * hinting algorithm and have the results rendered in horizontal LCD |
| * pixel mode, with code like |
| * |
| * ``` |
| * FT_Load_Glyph( face, glyph_index, |
| * load_flags | FT_LOAD_TARGET_LIGHT ); |
| * |
| * FT_Render_Glyph( face->glyph, FT_RENDER_MODE_LCD ); |
| * ``` |
| * |
| * In general, you should stick with one rendering mode. For example, |
| * switching between @FT_LOAD_TARGET_NORMAL and @FT_LOAD_TARGET_MONO |
| * enforces a lot of recomputation for TrueType fonts, which is slow. |
| * Another reason is caching: Selecting a different mode usually causes |
| * changes in both the outlines and the rasterized bitmaps; it is thus |
| * necessary to empty the cache after a mode switch to avoid false hits. |
| * |
| */ |
| #define FT_LOAD_TARGET_( x ) ( FT_STATIC_CAST( FT_Int32, (x) & 15 ) << 16 ) |
| |
| #define FT_LOAD_TARGET_NORMAL FT_LOAD_TARGET_( FT_RENDER_MODE_NORMAL ) |
| #define FT_LOAD_TARGET_LIGHT FT_LOAD_TARGET_( FT_RENDER_MODE_LIGHT ) |
| #define FT_LOAD_TARGET_MONO FT_LOAD_TARGET_( FT_RENDER_MODE_MONO ) |
| #define FT_LOAD_TARGET_LCD FT_LOAD_TARGET_( FT_RENDER_MODE_LCD ) |
| #define FT_LOAD_TARGET_LCD_V FT_LOAD_TARGET_( FT_RENDER_MODE_LCD_V ) |
| |
| |
| /************************************************************************** |
| * |
| * @macro: |
| * FT_LOAD_TARGET_MODE |
| * |
| * @description: |
| * Return the @FT_Render_Mode corresponding to a given |
| * @FT_LOAD_TARGET_XXX value. |
| * |
| */ |
| #define FT_LOAD_TARGET_MODE( x ) \ |
| FT_STATIC_CAST( FT_Render_Mode, ( (x) >> 16 ) & 15 ) |
| |
| |
| /************************************************************************** |
| * |
| * @function: |
| * FT_Set_Transform |
| * |
| * @description: |
| * Set the transformation that is applied to glyph images when they are |
| * loaded into a glyph slot through @FT_Load_Glyph. |
| * |
| * @inout: |
| * face :: |
| * A handle to the source face object. |
| * |
| * @input: |
| * matrix :: |
| * A pointer to the transformation's 2x2 matrix. Use `NULL` for the |
| * identity matrix. |
| * delta :: |
| * A pointer to the translation vector. Use `NULL` for the null |
| * vector. |
| * |
| * @note: |
| * This function is provided as a convenience, but keep in mind that |
| * @FT_Matrix coefficients are only 16.16 fixed-point values, which can |
| * limit the accuracy of the results. Using floating-point computations |
| * to perform the transform directly in client code instead will always |
| * yield better numbers. |
| * |
| * The transformation is only applied to scalable image formats after the |
| * glyph has been loaded. It means that hinting is unaltered by the |
| * transformation and is performed on the character size given in the |
| * last call to @FT_Set_Char_Size or @FT_Set_Pixel_Sizes. |
| * |
| * Note that this also transforms the `face.glyph.advance` field, but |
| * **not** the values in `face.glyph.metrics`. |
| */ |
| FT_EXPORT( void ) |
| FT_Set_Transform( FT_Face face, |
| FT_Matrix* matrix, |
| FT_Vector* delta ); |
| |
| |
| /************************************************************************** |
| * |
| * @function: |
| * FT_Get_Transform |
| * |
| * @description: |
| * Return the transformation that is applied to glyph images when they |
| * are loaded into a glyph slot through @FT_Load_Glyph. See |
| * @FT_Set_Transform for more details. |
| * |
| * @input: |
| * face :: |
| * A handle to the source face object. |
| * |
| * @output: |
| * matrix :: |
| * A pointer to a transformation's 2x2 matrix. Set this to NULL if you |
| * are not interested in the value. |
| * |
| * delta :: |
| * A pointer to a translation vector. Set this to NULL if you are not |
| * interested in the value. |
| * |
| * @since: |
| * 2.11 |
| * |
| */ |
| FT_EXPORT( void ) |
| FT_Get_Transform( FT_Face face, |
| FT_Matrix* matrix, |
| FT_Vector* delta ); |
| |
| |
| /************************************************************************** |
| * |
| * @enum: |
| * FT_Render_Mode |
| * |
| * @description: |
| * Render modes supported by FreeType~2. Each mode corresponds to a |
| * specific type of scanline conversion performed on the outline. |
| * |
| * For bitmap fonts and embedded bitmaps the `bitmap->pixel_mode` field |
| * in the @FT_GlyphSlotRec structure gives the format of the returned |
| * bitmap. |
| * |
| * All modes except @FT_RENDER_MODE_MONO use 256 levels of opacity, |
| * indicating pixel coverage. Use linear alpha blending and gamma |
| * correction to correctly render non-monochrome glyph bitmaps onto a |
| * surface; see @FT_Render_Glyph. |
| * |
| * The @FT_RENDER_MODE_SDF is a special render mode that uses up to 256 |
| * distance values, indicating the signed distance from the grid position |
| * to the nearest outline. |
| * |
| * @values: |
| * FT_RENDER_MODE_NORMAL :: |
| * Default render mode; it corresponds to 8-bit anti-aliased bitmaps. |
| * |
| * FT_RENDER_MODE_LIGHT :: |
| * This is equivalent to @FT_RENDER_MODE_NORMAL. It is only defined as |
| * a separate value because render modes are also used indirectly to |
| * define hinting algorithm selectors. See @FT_LOAD_TARGET_XXX for |
| * details. |
| * |
| * FT_RENDER_MODE_MONO :: |
| * This mode corresponds to 1-bit bitmaps (with 2~levels of opacity). |
| * |
| * FT_RENDER_MODE_LCD :: |
| * This mode corresponds to horizontal RGB and BGR subpixel displays |
| * like LCD screens. It produces 8-bit bitmaps that are 3~times the |
| * width of the original glyph outline in pixels, and which use the |
| * @FT_PIXEL_MODE_LCD mode. |
| * |
| * FT_RENDER_MODE_LCD_V :: |
| * This mode corresponds to vertical RGB and BGR subpixel displays |
| * (like PDA screens, rotated LCD displays, etc.). It produces 8-bit |
| * bitmaps that are 3~times the height of the original glyph outline in |
| * pixels and use the @FT_PIXEL_MODE_LCD_V mode. |
| * |
| * FT_RENDER_MODE_SDF :: |
| * This mode corresponds to 8-bit, single-channel signed distance field |
| * (SDF) bitmaps. Each pixel in the SDF grid is the value from the |
| * pixel's position to the nearest glyph's outline. The distances are |
| * calculated from the center of the pixel and are positive if they are |
| * filled by the outline (i.e., inside the outline) and negative |
| * otherwise. Check the note below on how to convert the output values |
| * to usable data. |
| * |
| * @note: |
| * The selected render mode only affects vector glyphs of a font. |
| * Embedded bitmaps often have a different pixel mode like |
| * @FT_PIXEL_MODE_MONO. You can use @FT_Bitmap_Convert to transform them |
| * into 8-bit pixmaps. |
| * |
| * For @FT_RENDER_MODE_SDF the output bitmap buffer contains normalized |
| * distances that are packed into unsigned 8-bit values. To get pixel |
| * values in floating point representation use the following pseudo-C |
| * code for the conversion. |
| * |
| * ``` |
| * // Load glyph and render using FT_RENDER_MODE_SDF, |
| * // then use the output buffer as follows. |
| * |
| * ... |
| * FT_Byte buffer = glyph->bitmap->buffer; |
| * |
| * |
| * for pixel in buffer |
| * { |
| * // `sd` is the signed distance and `spread` is the current spread; |
| * // the default spread is 2 and can be changed. |
| * |
| * float sd = (float)pixel - 128.0f; |
| * |
| * |
| * // Convert to pixel values. |
| * sd = ( sd / 128.0f ) * spread; |
| * |
| * // Store `sd` in a buffer or use as required. |
| * } |
| * |
| * ``` |
| * |
| * FreeType has two rasterizers for generating SDF, namely: |
| * |
| * 1. `sdf` for generating SDF directly from glyph's outline, and |
| * |
| * 2. `bsdf` for generating SDF from rasterized bitmaps. |
| * |
| * Depending on the glyph type (i.e., outline or bitmap), one of the two |
| * rasterizers is chosen at runtime and used for generating SDFs. To |
| * force the use of `bsdf` you should render the glyph with any of the |
| * FreeType's other rendering modes (e.g., `FT_RENDER_MODE_NORMAL`) and |
| * then re-render with `FT_RENDER_MODE_SDF`. |
| * |
| * There are some issues with stability and possible failures of the SDF |
| * renderers (specifically `sdf`). |
| * |
| * 1. The `sdf` rasterizer is sensitive to really small features (e.g., |
| * sharp turns that are less than 1~pixel) and imperfections in the |
| * glyph's outline, causing artifacts in the final output. |
| * |
| * 2. The `sdf` rasterizer has limited support for handling intersecting |
| * contours and *cannot* handle self-intersecting contours whatsoever. |
| * Self-intersection happens when a single connected contour |
| * intersects itself at some point; having these in your font |
| * definitely poses a problem to the rasterizer and cause artifacts, |
| * too. |
| * |
| * 3. Generating SDF for really small glyphs may result in undesirable |
| * output; the pixel grid (which stores distance information) becomes |
| * too coarse. |
| * |
| * 4. Since the output buffer is normalized, precision at smaller spreads |
| * is greater than precision at larger spread values because the |
| * output range of [0..255] gets mapped to a smaller SDF range. A |
| * spread of~2 should be sufficient in most cases. |
| * |
| * Points (1) and (2) can be avoided by using the `bsdf` rasterizer, |
| * which is more stable than the `sdf` rasterizer in general. |
| * |
| */ |
| typedef enum FT_Render_Mode_ |
| { |
| FT_RENDER_MODE_NORMAL = 0, |
| FT_RENDER_MODE_LIGHT, |
| FT_RENDER_MODE_MONO, |
| FT_RENDER_MODE_LCD, |
| FT_RENDER_MODE_LCD_V, |
| FT_RENDER_MODE_SDF, |
| |
| FT_RENDER_MODE_MAX |
| |
| } FT_Render_Mode; |
| |
| |
| /* these constants are deprecated; use the corresponding */ |
| /* `FT_Render_Mode` values instead */ |
| #define ft_render_mode_normal FT_RENDER_MODE_NORMAL |
| #define ft_render_mode_mono FT_RENDER_MODE_MONO |
| |
| |
| /************************************************************************** |
| * |
| * @function: |
| * FT_Render_Glyph |
| * |
| * @description: |
| * Convert a given glyph image to a bitmap. It does so by inspecting the |
| * glyph image format, finding the relevant renderer, and invoking it. |
| * |
| * @inout: |
| * slot :: |
| * A handle to the glyph slot containing the image to convert. |
| * |
| * @input: |
| * render_mode :: |
| * The render mode used to render the glyph image into a bitmap. See |
| * @FT_Render_Mode for a list of possible values. |
| * |
| * If @FT_RENDER_MODE_NORMAL is used, a previous call of @FT_Load_Glyph |
| * with flag @FT_LOAD_COLOR makes `FT_Render_Glyph` provide a default |
| * blending of colored glyph layers associated with the current glyph |
| * slot (provided the font contains such layers) instead of rendering |
| * the glyph slot's outline. This is an experimental feature; see |
| * @FT_LOAD_COLOR for more information. |
| * |
| * @return: |
| * FreeType error code. 0~means success. |
| * |
| * @note: |
| * When FreeType outputs a bitmap of a glyph, it really outputs an alpha |
| * coverage map. If a pixel is completely covered by a filled-in |
| * outline, the bitmap contains 0xFF at that pixel, meaning that |
| * 0xFF/0xFF fraction of that pixel is covered, meaning the pixel is 100% |
| * black (or 0% bright). If a pixel is only 50% covered (value 0x80), |
| * the pixel is made 50% black (50% bright or a middle shade of grey). |
| * 0% covered means 0% black (100% bright or white). |
| * |
| * On high-DPI screens like on smartphones and tablets, the pixels are so |
| * small that their chance of being completely covered and therefore |
| * completely black are fairly good. On the low-DPI screens, however, |
| * the situation is different. The pixels are too large for most of the |
| * details of a glyph and shades of gray are the norm rather than the |
| * exception. |
| * |
| * This is relevant because all our screens have a second problem: they |
| * are not linear. 1~+~1 is not~2. Twice the value does not result in |
| * twice the brightness. When a pixel is only 50% covered, the coverage |
| * map says 50% black, and this translates to a pixel value of 128 when |
| * you use 8~bits per channel (0-255). However, this does not translate |
| * to 50% brightness for that pixel on our sRGB and gamma~2.2 screens. |
| * Due to their non-linearity, they dwell longer in the darks and only a |
| * pixel value of about 186 results in 50% brightness -- 128 ends up too |
| * dark on both bright and dark backgrounds. The net result is that dark |
| * text looks burnt-out, pixely and blotchy on bright background, bright |
| * text too frail on dark backgrounds, and colored text on colored |
| * background (for example, red on green) seems to have dark halos or |
| * 'dirt' around it. The situation is especially ugly for diagonal stems |
| * like in 'w' glyph shapes where the quality of FreeType's anti-aliasing |
| * depends on the correct display of grays. On high-DPI screens where |
| * smaller, fully black pixels reign supreme, this doesn't matter, but on |
| * our low-DPI screens with all the gray shades, it does. 0% and 100% |
| * brightness are the same things in linear and non-linear space, just |
| * all the shades in-between aren't. |
| * |
| * The blending function for placing text over a background is |
| * |
| * ``` |
| * dst = alpha * src + (1 - alpha) * dst , |
| * ``` |
| * |
| * which is known as the OVER operator. |
| * |
| * To correctly composite an anti-aliased pixel of a glyph onto a |
| * surface, |
| * |
| * 1. take the foreground and background colors (e.g., in sRGB space) |
| * and apply gamma to get them in a linear space, |
| * |
| * 2. use OVER to blend the two linear colors using the glyph pixel |
| * as the alpha value (remember, the glyph bitmap is an alpha coverage |
| * bitmap), and |
| * |
| * 3. apply inverse gamma to the blended pixel and write it back to |
| * the image. |
| * |
| * Internal testing at Adobe found that a target inverse gamma of~1.8 for |
| * step~3 gives good results across a wide range of displays with an sRGB |
| * gamma curve or a similar one. |
| * |
| * This process can cost performance. There is an approximation that |
| * does not need to know about the background color; see |
| * https://bel.fi/alankila/lcd/ and |
| * https://bel.fi/alankila/lcd/alpcor.html for details. |
| * |
| * **ATTENTION**: Linear blending is even more important when dealing |
| * with subpixel-rendered glyphs to prevent color-fringing! A |
| * subpixel-rendered glyph must first be filtered with a filter that |
| * gives equal weight to the three color primaries and does not exceed a |
| * sum of 0x100, see section @lcd_rendering. Then the only difference to |
| * gray linear blending is that subpixel-rendered linear blending is done |
| * 3~times per pixel: red foreground subpixel to red background subpixel |
| * and so on for green and blue. |
| */ |
| FT_EXPORT( FT_Error ) |
| FT_Render_Glyph( FT_GlyphSlot slot, |
| FT_Render_Mode render_mode ); |
| |
| |
| /************************************************************************** |
| * |
| * @enum: |
| * FT_Kerning_Mode |
| * |
| * @description: |
| * An enumeration to specify the format of kerning values returned by |
| * @FT_Get_Kerning. |
| * |
| * @values: |
| * FT_KERNING_DEFAULT :: |
| * Return grid-fitted kerning distances in 26.6 fractional pixels. |
| * |
| * FT_KERNING_UNFITTED :: |
| * Return un-grid-fitted kerning distances in 26.6 fractional pixels. |
| * |
| * FT_KERNING_UNSCALED :: |
| * Return the kerning vector in original font units. |
| * |
| * @note: |
| * `FT_KERNING_DEFAULT` returns full pixel values; it also makes FreeType |
| * heuristically scale down kerning distances at small ppem values so |
| * that they don't become too big. |
| * |
| * Both `FT_KERNING_DEFAULT` and `FT_KERNING_UNFITTED` use the current |
| * horizontal scaling factor (as set e.g. with @FT_Set_Char_Size) to |
| * convert font units to pixels. |
| */ |
| typedef enum FT_Kerning_Mode_ |
| { |
| FT_KERNING_DEFAULT = 0, |
| FT_KERNING_UNFITTED, |
| FT_KERNING_UNSCALED |
| |
| } FT_Kerning_Mode; |
| |
| |
| /* these constants are deprecated; use the corresponding */ |
| /* `FT_Kerning_Mode` values instead */ |
| #define ft_kerning_default FT_KERNING_DEFAULT |
| #define ft_kerning_unfitted FT_KERNING_UNFITTED |
| #define ft_kerning_unscaled FT_KERNING_UNSCALED |
| |
| |
| /************************************************************************** |
| * |
| * @function: |
| * FT_Get_Kerning |
| * |
| * @description: |
| * Return the kerning vector between two glyphs of the same face. |
| * |
| * @input: |
| * face :: |
| * A handle to a source face object. |
| * |
| * left_glyph :: |
| * The index of the left glyph in the kern pair. |
| * |
| * right_glyph :: |
| * The index of the right glyph in the kern pair. |
| * |
| * kern_mode :: |
| * See @FT_Kerning_Mode for more information. Determines the scale and |
| * dimension of the returned kerning vector. |
| * |
| * @output: |
| * akerning :: |
| * The kerning vector. This is either in font units, fractional pixels |
| * (26.6 format), or pixels for scalable formats, and in pixels for |
| * fixed-sizes formats. |
| * |
| * @return: |
| * FreeType error code. 0~means success. |
| * |
| * @note: |
| * Only horizontal layouts (left-to-right & right-to-left) are supported |
| * by this method. Other layouts, or more sophisticated kernings, are |
| * out of the scope of this API function -- they can be implemented |
| * through format-specific interfaces. |
| * |
| * Kerning for OpenType fonts implemented in a 'GPOS' table is not |
| * supported; use @FT_HAS_KERNING to find out whether a font has data |
| * that can be extracted with `FT_Get_Kerning`. |
| */ |
| FT_EXPORT( FT_Error ) |
| FT_Get_Kerning( FT_Face face, |
| FT_UInt left_glyph, |
| FT_UInt right_glyph, |
| FT_UInt kern_mode, |
| FT_Vector *akerning ); |
| |
| |
| /************************************************************************** |
| * |
| * @function: |
| * FT_Get_Track_Kerning |
| * |
| * @description: |
| * Return the track kerning for a given face object at a given size. |
| * |
| * @input: |
| * face :: |
| * A handle to a source face object. |
| * |
| * point_size :: |
| * The point size in 16.16 fractional points. |
| * |
| * degree :: |
| * The degree of tightness. Increasingly negative values represent |
| * tighter track kerning, while increasingly positive values represent |
| * looser track kerning. Value zero means no track kerning. |
| * |
| * @output: |
| * akerning :: |
| * The kerning in 16.16 fractional points, to be uniformly applied |
| * between all glyphs. |
| * |
| * @return: |
| * FreeType error code. 0~means success. |
| * |
| * @note: |
| * Currently, only the Type~1 font driver supports track kerning, using |
| * data from AFM files (if attached with @FT_Attach_File or |
| * @FT_Attach_Stream). |
| * |
| * Only very few AFM files come with track kerning data; please refer to |
| * Adobe's AFM specification for more details. |
| */ |
| FT_EXPORT( FT_Error ) |
| FT_Get_Track_Kerning( FT_Face face, |
| FT_Fixed point_size, |
| FT_Int degree, |
| FT_Fixed* akerning ); |
| |
| |
| /************************************************************************** |
| * |
| * @function: |
| * FT_Select_Charmap |
| * |
| * @description: |
| * Select a given charmap by its encoding tag (as listed in |
| * `freetype.h`). |
| * |
| * @inout: |
| * face :: |
| * A handle to the source face object. |
| * |
| * @input: |
| * encoding :: |
| * A handle to the selected encoding. |
| * |
| * @return: |
| * FreeType error code. 0~means success. |
| * |
| * @note: |
| * This function returns an error if no charmap in the face corresponds |
| * to the encoding queried here. |
| * |
| * Because many fonts contain more than a single cmap for Unicode |
| * encoding, this function has some special code to select the one that |
| * covers Unicode best ('best' in the sense that a UCS-4 cmap is |
| * preferred to a UCS-2 cmap). It is thus preferable to @FT_Set_Charmap |
| * in this case. |
| */ |
| FT_EXPORT( FT_Error ) |
| FT_Select_Charmap( FT_Face face, |
| FT_Encoding encoding ); |
| |
| |
| /************************************************************************** |
| * |
| * @function: |
| * FT_Set_Charmap |
| * |
| * @description: |
| * Select a given charmap for character code to glyph index mapping. |
| * |
| * @inout: |
| * face :: |
| * A handle to the source face object. |
| * |
| * @input: |
| * charmap :: |
| * A handle to the selected charmap. |
| * |
| * @return: |
| * FreeType error code. 0~means success. |
| * |
| * @note: |
| * This function returns an error if the charmap is not part of the face |
| * (i.e., if it is not listed in the `face->charmaps` table). |
| * |
| * It also fails if an OpenType type~14 charmap is selected (which |
| * doesn't map character codes to glyph indices at all). |
| */ |
| FT_EXPORT( FT_Error ) |
| FT_Set_Charmap( FT_Face face, |
| FT_CharMap charmap ); |
| |
| |
| /************************************************************************** |
| * |
| * @function: |
| * FT_Get_Charmap_Index |
| * |
| * @description: |
| * Retrieve index of a given charmap. |
| * |
| * @input: |
| * charmap :: |
| * A handle to a charmap. |
| * |
| * @return: |
| * The index into the array of character maps within the face to which |
| * `charmap` belongs. If an error occurs, -1 is returned. |
| * |
| */ |
| FT_EXPORT( FT_Int ) |
| FT_Get_Charmap_Index( FT_CharMap charmap ); |
| |
| |
| /************************************************************************** |
| * |
| * @function: |
| * FT_Get_Char_Index |
| * |
| * @description: |
| * Return the glyph index of a given character code. This function uses |
| * the currently selected charmap to do the mapping. |
| * |
| * @input: |
| * face :: |
| * A handle to the source face object. |
| * |
| * charcode :: |
| * The character code. |
| * |
| * @return: |
| * The glyph index. 0~means 'undefined character code'. |
| * |
| * @note: |
| * If you use FreeType to manipulate the contents of font files directly, |
| * be aware that the glyph index returned by this function doesn't always |
| * correspond to the internal indices used within the file. This is done |
| * to ensure that value~0 always corresponds to the 'missing glyph'. If |
| * the first glyph is not named '.notdef', then for Type~1 and Type~42 |
| * fonts, '.notdef' will be moved into the glyph ID~0 position, and |
| * whatever was there will be moved to the position '.notdef' had. For |
| * Type~1 fonts, if there is no '.notdef' glyph at all, then one will be |
| * created at index~0 and whatever was there will be moved to the last |
| * index -- Type~42 fonts are considered invalid under this condition. |
| */ |
| FT_EXPORT( FT_UInt ) |
| FT_Get_Char_Index( FT_Face face, |
| FT_ULong charcode ); |
| |
| |
| /************************************************************************** |
| * |
| * @function: |
| * FT_Get_First_Char |
| * |
| * @description: |
| * Return the first character code in the current charmap of a given |
| * face, together with its corresponding glyph index. |
| * |
| * @input: |
| * face :: |
| * A handle to the source face object. |
| * |
| * @output: |
| * agindex :: |
| * Glyph index of first character code. 0~if charmap is empty. |
| * |
| * @return: |
| * The charmap's first character code. |
| * |
| * @note: |
| * You should use this function together with @FT_Get_Next_Char to parse |
| * all character codes available in a given charmap. The code should |
| * look like this: |
| * |
| * ``` |
| * FT_ULong charcode; |
| * FT_UInt gindex; |
| * |
| * |
| * charcode = FT_Get_First_Char( face, &gindex ); |
| * while ( gindex != 0 ) |
| * { |
| * ... do something with (charcode,gindex) pair ... |
| * |
| * charcode = FT_Get_Next_Char( face, charcode, &gindex ); |
| * } |
| * ``` |
| * |
| * Be aware that character codes can have values up to 0xFFFFFFFF; this |
| * might happen for non-Unicode or malformed cmaps. However, even with |
| * regular Unicode encoding, so-called 'last resort fonts' (using SFNT |
| * cmap format 13, see function @FT_Get_CMap_Format) normally have |
| * entries for all Unicode characters up to 0x1FFFFF, which can cause *a |
| * lot* of iterations. |
| * |
| * Note that `*agindex` is set to~0 if the charmap is empty. The result |
| * itself can be~0 in two cases: if the charmap is empty or if the |
| * value~0 is the first valid character code. |
| */ |
| FT_EXPORT( FT_ULong ) |
| FT_Get_First_Char( FT_Face face, |
| FT_UInt *agindex ); |
| |
| |
| /************************************************************************** |
| * |
| * @function: |
| * FT_Get_Next_Char |
| * |
| * @description: |
| * Return the next character code in the current charmap of a given face |
| * following the value `char_code`, as well as the corresponding glyph |
| * index. |
| * |
| * @input: |
| * face :: |
| * A handle to the source face object. |
| * |
| * char_code :: |
| * The starting character code. |
| * |
| * @output: |
| * agindex :: |
| * Glyph index of next character code. 0~if charmap is empty. |
| * |
| * @return: |
| * The charmap's next character code. |
| * |
| * @note: |
| * You should use this function with @FT_Get_First_Char to walk over all |
|